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All questions of September Week 3 for NEET Exam
The correct IUPAC name of the complex Fe(C5H5)2 is _- a)Cyclopentadienyl iron (II)
- b)Bis (cyclopentadienyl) iron (II)
- c)Dicyclopentadiency ferrate (II)
- d)Ferrocene
Correct answer is option 'B'. Can you explain this answer?
The correct IUPAC name of the complex Fe(C5H5)2 is _
a)
Cyclopentadienyl iron (II)
b)
Bis (cyclopentadienyl) iron (II)
c)
Dicyclopentadiency ferrate (II)
d)
Ferrocene
|
Alok Mehta answered |
The iron complex may be treated as cationic part, and C5H5- is a bidentate ligand therefore name can be assigned as follows “dicyclopentadienyl Iron (II) cation”.
The hybrisation of Co in [Co(H2O)6]3+ is :
- a)d2sp3
- b)dsp2
- c)dsp3
- d)spd3
Correct answer is option 'A'. Can you explain this answer?
The hybrisation of Co in [Co(H2O)6]3+ is :
a)
d2sp3
b)
dsp2
c)
dsp3
d)
spd3
|
Rajeev Saxena answered |
In this complex compound the total charge is +3 as H2O is a neutral compound so the oxidation state of cobalt is +3 and the electronic configuration of Co is 3d7 4s2. So, Co(+3)=4d6 and H2O is a weak ligand so there is no pairing of electron. So,4s 4p3 and 4d2 orbital make hybrid orbital to have a hybridization of d2sp3.
An air-cored solenoid with length 30 cm, area of cross-section 25 cm2 and number of turns 500, carries a current of 2.5 A. The current is suddenly switched off in a brief time of 10−3s. Average back emf induced across the ends of the open switch in the circuit is- a)6.5 V .
- b)4.6 V
- c)4.5 V
- d)5 V3.
Correct answer is option 'A'. Can you explain this answer?
An air-cored solenoid with length 30 cm, area of cross-section 25 cm2 and number of turns 500, carries a current of 2.5 A. The current is suddenly switched off in a brief time of 10−3s. Average back emf induced across the ends of the open switch in the circuit is
a)
6.5 V .
b)
4.6 V
c)
4.5 V
d)
5 V3.
|
Arka Das answered |
-4 seconds. Find the average induced emf in the solenoid during this time.
We can use Faraday's law of induction to find the average induced emf in the solenoid:
emf = -N (ΔΦ/Δt)
where N is the number of turns, ΔΦ is the change in magnetic flux, and Δt is the time interval.
Since the current is suddenly switched off, the magnetic flux through the solenoid changes from its maximum value to zero. The maximum value of magnetic flux through the solenoid is given by:
Φ = B A
where B is the magnetic field strength and A is the area of cross-section. Since the solenoid is air-cored, the magnetic field is given by:
B = μ0 N I / L
where μ0 is the permeability of free space, I is the current, and L is the length of the solenoid. Substituting the given values, we get:
B = (4π × 10^-7) × 500 × 2.5 / 0.3 = 1.05 T
Therefore, the maximum magnetic flux through the solenoid is:
Φ = 1.05 × 25 × 10^-4 = 2.625 × 10^-5 Wb
During the brief time of 10^-4 seconds, the change in magnetic flux is equal to the maximum flux, since the current is switched off suddenly. Therefore, ΔΦ = 2.625 × 10^-5 Wb.
Substituting the given values in the formula for emf, we get:
emf = -500 (2.625 × 10^-5) / (10^-4) = -1.3125 V
Therefore, the average induced emf in the solenoid during the brief time of 10^-4 seconds is 1.3125 V. Note that the negative sign indicates that the induced emf opposes the change in current.
We can use Faraday's law of induction to find the average induced emf in the solenoid:
emf = -N (ΔΦ/Δt)
where N is the number of turns, ΔΦ is the change in magnetic flux, and Δt is the time interval.
Since the current is suddenly switched off, the magnetic flux through the solenoid changes from its maximum value to zero. The maximum value of magnetic flux through the solenoid is given by:
Φ = B A
where B is the magnetic field strength and A is the area of cross-section. Since the solenoid is air-cored, the magnetic field is given by:
B = μ0 N I / L
where μ0 is the permeability of free space, I is the current, and L is the length of the solenoid. Substituting the given values, we get:
B = (4π × 10^-7) × 500 × 2.5 / 0.3 = 1.05 T
Therefore, the maximum magnetic flux through the solenoid is:
Φ = 1.05 × 25 × 10^-4 = 2.625 × 10^-5 Wb
During the brief time of 10^-4 seconds, the change in magnetic flux is equal to the maximum flux, since the current is switched off suddenly. Therefore, ΔΦ = 2.625 × 10^-5 Wb.
Substituting the given values in the formula for emf, we get:
emf = -500 (2.625 × 10^-5) / (10^-4) = -1.3125 V
Therefore, the average induced emf in the solenoid during the brief time of 10^-4 seconds is 1.3125 V. Note that the negative sign indicates that the induced emf opposes the change in current.
From the stability constant (hypothetical values), given below, predict which is the strongest ligand:- a)Cu2+ + 4NH3
[Cu(NH3)4]2+, K = 4.5 × 1011 - b)Cu2+ + 4CN-
[Cu(CN)4]2- , K = 2.0 × 1027 - c)Cu2+ + 2en
[Cu(en)2]2+, K = 3.0 × 1015 - d)Cu2+ + 4H2O
[Cu(H2O)4]2+, K = 9.5 × 108
Correct answer is option 'B'. Can you explain this answer?
From the stability constant (hypothetical values), given below, predict which is the strongest ligand:
a)
Cu2+ + 4NH3 [Cu(NH3)4]2+, K = 4.5 × 1011
[Cu(NH3)4]2+, K = 4.5 × 1011b)
Cu2+ + 4CN- [Cu(CN)4]2- , K = 2.0 × 1027
[Cu(CN)4]2- , K = 2.0 × 1027c)
Cu2+ + 2en [Cu(en)2]2+, K = 3.0 × 1015
[Cu(en)2]2+, K = 3.0 × 1015d)
Cu2+ + 4H2O [Cu(H2O)4]2+, K = 9.5 × 108
[Cu(H2O)4]2+, K = 9.5 × 108
|
Raghav Yadav answered |
Higher the value of K higher will be strength of ligand & more will be thermodynamic stability of complex produced.
A circular coil of radius 8.0 cm and 20 turns is rotated about its vertical diameter with an angular speed of 50 rad s-1 in a uniform horizontal magnetic field of magnitude 3×10-2 T. If the coil resistance is 10Ω, maximum emf induced in the coil,maximum value of current in the coil and average power loss due to Joule heating are- a)0.603 V, 0.0303 A,0.018 W
- b)0.603 V, 0.0603 A,0.038 W
- c)0.603 V, 0.0603 A,0.018 W .
- d)0.303 V, 0.0603 A,0.018 W
Correct answer is option 'C'. Can you explain this answer?
A circular coil of radius 8.0 cm and 20 turns is rotated about its vertical diameter with an angular speed of 50 rad s-1 in a uniform horizontal magnetic field of magnitude 3×10-2 T. If the coil resistance is 10Ω, maximum emf induced in the coil,maximum value of current in the coil and average power loss due to Joule heating are
a)
0.603 V, 0.0303 A,0.018 W
b)
0.603 V, 0.0603 A,0.038 W
c)
0.603 V, 0.0603 A,0.018 W .
d)
0.303 V, 0.0603 A,0.018 W
|
Bhavana Banerjee answered |
e = NBAω = 20 x 3 x 10-2 x (3.14 x 0.08 x 0.08) x 50 = 0.603C
average power loss due to joule heating
In the complex Fe(CO)x, the value of x is :- a)3
- b)4
- c)5
- d)6
Correct answer is option 'C'. Can you explain this answer?
In the complex Fe(CO)x, the value of x is :
a)
3
b)
4
c)
5
d)
6
|
Aarya Dasgupta answered |
[Fe(CO)x]0
EAN = 26 + 2x = 36
x = 5
EAN = 26 + 2x = 36
x = 5
Which of the following is π complex :- a)Trimethyl aluminium
- b)Ferrocene
- c)Diethyl zinc
- d)Nickel tetra carbonyl
Correct answer is option 'B'. Can you explain this answer?
Which of the following is π complex :
a)
Trimethyl aluminium
b)
Ferrocene
c)
Diethyl zinc
d)
Nickel tetra carbonyl
|
Nidhi Nambiar answered |
Al(C2H5)3 σ - complex
Fe(C5H5)2 π - complex
Zn(C2H5)2 σ - complex
[Ni(CO)4] σ - complex
Fe(C5H5)2 π - complex
Zn(C2H5)2 σ - complex
[Ni(CO)4] σ - complex
For the complex ion dichlorido bis (ethylene diamine) cobalt (III), select the correct statement.- a)It has three isomers, two of them are optically active and one is optically inactive.
- b)It has three isomers, all of them are optically active.
- c)It has three isomers, all of them are optically inactive.
- d)It has one optically active isomer and two geometrical isomers.
Correct answer is option 'A'. Can you explain this answer?
For the complex ion dichlorido bis (ethylene diamine) cobalt (III), select the correct statement.
a)
It has three isomers, two of them are optically active and one is optically inactive.
b)
It has three isomers, all of them are optically active.
c)
It has three isomers, all of them are optically inactive.
d)
It has one optically active isomer and two geometrical isomers.
|
Milan Datta answered |
Explanation:
The complex ion dichlorido bis(ethylene diamine) cobalt (III) has the formula [Co(en)2Cl2]+. Let's analyze the structure and isomers of this complex ion to determine the correct statement.
Structure:
The central cobalt (III) ion is coordinated by two ethylenediamine (en) ligands and two chloride (Cl) ligands. The ethylenediamine ligand is a bidentate ligand, meaning that it can form two coordination bonds with the central metal ion. The chloride ligand is a monodentate ligand, meaning that it can form only one coordination bond with the central metal ion.
Isomers:
Isomers are compounds that have the same chemical formula but different structural arrangements. In this case, there are three possible isomers for the complex ion [Co(en)2Cl2]+.
1. Geometrical isomerism:
Geometrical isomerism occurs when there is restricted rotation around a bond, resulting in different spatial arrangements. In the case of [Co(en)2Cl2]+, there are two possible geometrical isomers:
- cis-[Co(en)2Cl2]+: In this isomer, the two ethylenediamine ligands are adjacent to each other, and the two chloride ligands are also adjacent to each other.
- trans-[Co(en)2Cl2]+: In this isomer, the two ethylenediamine ligands are opposite to each other, and the two chloride ligands are also opposite to each other.
2. Optical isomerism:
Optical isomerism occurs when a compound is chiral, meaning it does not possess a plane of symmetry. Chiral compounds exist in two forms known as enantiomers, which are mirror images of each other. In the case of [Co(en)2Cl2]+, there is only one chiral center, which is the cobalt ion.
- Each geometrical isomer can exist as either an R or S enantiomer, resulting in two optically active isomers.
- The trans-[Co(en)2Cl2]+ isomer is optically inactive because its mirror image can be superimposed on it.
Conclusion:
Based on the analysis, the correct statement is option A. The complex ion dichlorido bis(ethylene diamine) cobalt (III) has three isomers, two of them are optically active (cis-[Co(en)2Cl2]+ R and S enantiomers) and one is optically inactive (trans-[Co(en)2Cl2]+).
The complex ion dichlorido bis(ethylene diamine) cobalt (III) has the formula [Co(en)2Cl2]+. Let's analyze the structure and isomers of this complex ion to determine the correct statement.
Structure:
The central cobalt (III) ion is coordinated by two ethylenediamine (en) ligands and two chloride (Cl) ligands. The ethylenediamine ligand is a bidentate ligand, meaning that it can form two coordination bonds with the central metal ion. The chloride ligand is a monodentate ligand, meaning that it can form only one coordination bond with the central metal ion.
Isomers:
Isomers are compounds that have the same chemical formula but different structural arrangements. In this case, there are three possible isomers for the complex ion [Co(en)2Cl2]+.
1. Geometrical isomerism:
Geometrical isomerism occurs when there is restricted rotation around a bond, resulting in different spatial arrangements. In the case of [Co(en)2Cl2]+, there are two possible geometrical isomers:
- cis-[Co(en)2Cl2]+: In this isomer, the two ethylenediamine ligands are adjacent to each other, and the two chloride ligands are also adjacent to each other.
- trans-[Co(en)2Cl2]+: In this isomer, the two ethylenediamine ligands are opposite to each other, and the two chloride ligands are also opposite to each other.
2. Optical isomerism:
Optical isomerism occurs when a compound is chiral, meaning it does not possess a plane of symmetry. Chiral compounds exist in two forms known as enantiomers, which are mirror images of each other. In the case of [Co(en)2Cl2]+, there is only one chiral center, which is the cobalt ion.
- Each geometrical isomer can exist as either an R or S enantiomer, resulting in two optically active isomers.
- The trans-[Co(en)2Cl2]+ isomer is optically inactive because its mirror image can be superimposed on it.
Conclusion:
Based on the analysis, the correct statement is option A. The complex ion dichlorido bis(ethylene diamine) cobalt (III) has three isomers, two of them are optically active (cis-[Co(en)2Cl2]+ R and S enantiomers) and one is optically inactive (trans-[Co(en)2Cl2]+).
The structure of iron pentacarbonyl is :- a)Square pyramidal
- b)Trigonal bipyramidal
- c)Squrare planar
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
The structure of iron pentacarbonyl is :
a)
Square pyramidal
b)
Trigonal bipyramidal
c)
Squrare planar
d)
None of these
|
Geetika Shah answered |
[Fe(CO)5] TBP
CO is strong field ligand
Fe - 3d64s2
CO is strong field ligand
Fe - 3d64s2
electromagnetic induction i.e currents can be induced in coils (Select the best)- a)Only if the coil moves
- b)Only if the coil moves and magnet also moves in the same direction
- c)if relative motion of coil and magnet is present.
- d)Only if the magnet moves
Correct answer is option 'C'. Can you explain this answer?
electromagnetic induction i.e currents can be induced in coils (Select the best)
a)
Only if the coil moves
b)
Only if the coil moves and magnet also moves in the same direction
c)
if relative motion of coil and magnet is present.
d)
Only if the magnet moves
|
Ezhil The Champ answered |
Consider a cylindrical copper coil connected serially to a galvanometer . a strong magnet with north or south pole is taken towards it. and coil is moved up and down.
when ever there is a relative motion between coil and the magnet the galvanometer shows deflection . indicating flow of induced current.
the deflection is momentary . it last so long as there is relative motion between coil and magnet.
the direction of induced current changes if magnet or coil is moved towards or away frm it
the deflection is more when the relative motion is faster or less when it is slow.
t
when ever there is a relative motion between coil and the magnet the galvanometer shows deflection . indicating flow of induced current.
the deflection is momentary . it last so long as there is relative motion between coil and magnet.
the direction of induced current changes if magnet or coil is moved towards or away frm it
the deflection is more when the relative motion is faster or less when it is slow.
t
In the developmental history of mammalian heart, it is observed that it passes through a two chambered fish like heart, three chambered frog like heart and finally four chambered stage
To which hypothesis can this above cited statement be approximated?- a)Lamarck's principle
- b)Mendelian principle
- c)Biogenetic law
- d)Hardy Weinberg law
Correct answer is option 'C'. Can you explain this answer?
In the developmental history of mammalian heart, it is observed that it passes through a two chambered fish like heart, three chambered frog like heart and finally four chambered stage
To which hypothesis can this above cited statement be approximated?
To which hypothesis can this above cited statement be approximated?
a)
Lamarck's principle
b)
Mendelian principle
c)
Biogenetic law
d)
Hardy Weinberg law
|
Vivek Patel answered |
Biogenetic law or Recapitulation theory was given by Ernst Haeckel in 1866. It states that 'ontogeny repeats phylogeny'. Ontogeny is the life history of an organism while phylogeny is the evolutionary history of the race of that organism. This means that an organism repeats its ancestral history during its development.
The oxidation state of Mo in its oxo-complex species [Mo2O4(C2H4 )2(H2O)2]2- is :- a)+2
- b)+3
- c)+4
- d)+5
Correct answer is option 'B'. Can you explain this answer?
The oxidation state of Mo in its oxo-complex species [Mo2O4(C2H4 )2(H2O)2]2- is :
a)
+2
b)
+3
c)
+4
d)
+5
|
Charvi Ahuja answered |
Let the O. N. of Mo in the complex is x
2x + (–2) × 2 + 0 × 2 + 0 × 2 = – 2
2x + (–2) × 2 + 0 × 2 + 0 × 2 = – 2
The EAN of platinum in potassium hexachloroplatinate (IV) is :- a)46
- b)86
- c)36
- d)84
Correct answer is option 'B'. Can you explain this answer?
The EAN of platinum in potassium hexachloroplatinate (IV) is :
a)
46
b)
86
c)
36
d)
84
|
Dishani Kulkarni answered |
K2+4[PtCl6]
At No. Pt = 78
EAN = 78 – 4 + 6 × 2 = 86
At No. Pt = 78
EAN = 78 – 4 + 6 × 2 = 86
In which of the following complexes the nickel metal is in highest oxidation state.- a)Ni(CO)4
- b)[Cr(NH3)6]2[NiF 6]3
- c)[Ni(NH3)6](BF4) 2
- d)K4[Ni(CN)6]
Correct answer is option 'B'. Can you explain this answer?
In which of the following complexes the nickel metal is in highest oxidation state.
a)
Ni(CO)4
b)
[Cr(NH3)6]2[NiF 6]3
c)
[Ni(NH3)6](BF4) 2
d)
K4[Ni(CN)6]
|
Sankar Gupta answered |
[Ni0(CO)4]
[Cr3+(NH3)2][Ni4+F6]3
[Ni2+(NH3)2][B+3F4]2
K4[Ni+2(CN)6]
[Cr3+(NH3)2][Ni4+F6]3
[Ni2+(NH3)2][B+3F4]2
K4[Ni+2(CN)6]
Type of isomerism exhibited by [Cr(NCS)(NH3)5] [ZnCl4] :- a)Coordination isomerism
- b)Linkage isomerism
- c)Ionization isomerism
- d)Both coordination and linkage isomerism
Correct answer is option 'D'. Can you explain this answer?
Type of isomerism exhibited by [Cr(NCS)(NH3)5] [ZnCl4] :
a)
Coordination isomerism
b)
Linkage isomerism
c)
Ionization isomerism
d)
Both coordination and linkage isomerism
|
Shail Chakraborty answered |
Since both cation & anion constitute coordination sphere so it exhibit coordination isomerism and contains ambident ligand so, it shows linkage isomerism
Which of the following complex exhibits geometrical isomerism:- a)[Zn(gly)2]
- b)[Cu(en)(NH3)2]+
- c)[PtBrCl(NH3)(py)]
- d)[Ni(CN)2(CO)2]2-
Correct answer is option 'C'. Can you explain this answer?
Which of the following complex exhibits geometrical isomerism:
a)
[Zn(gly)2]
b)
[Cu(en)(NH3)2]+
c)
[PtBrCl(NH3)(py)]
d)
[Ni(CN)2(CO)2]2-
|
|
Nidhi Nambiar answered |
[PtBrCl NH3 Py] Pt2+ is dsp2 hybridised & hence geometry is square planner & sq. planner complex with four different ligands shows geometrical isomerism.
Which one of the following describes correctly the homologous structures?- a)Organs with anatomical similarities, but performing different functions
- b)Organs with anatomical dissimilarities, but performing same function
- c)Organs that have no function now, but had important function in ancestors
- d)Organs appearing only in embryonic stage and disappearing later in the adult
Correct answer is option 'A'. Can you explain this answer?
Which one of the following describes correctly the homologous structures?
a)
Organs with anatomical similarities, but performing different functions
b)
Organs with anatomical dissimilarities, but performing same function
c)
Organs that have no function now, but had important function in ancestors
d)
Organs appearing only in embryonic stage and disappearing later in the adult
|
Vandana Chakraborty answered |
Homologous structures are organs or body parts that have similar anatomical structures but may have different functions. These structures are often found in different species that share a common ancestor. The correct answer is option A, which states that homologous structures are organs with anatomical similarities but performing different functions.
Explanation:
1. Definition of homologous structures:
- Homologous structures refer to organs or body parts that have similar structural features, indicating a common evolutionary origin.
- These structures may have been modified over time to perform different functions in different species.
2. Anatomical similarities:
- Homologous structures exhibit similarities in their basic structure, such as the arrangement of bones, muscles, or other tissues.
- These similarities suggest that these structures evolved from a common ancestor.
3. Different functions:
- Despite their similarities in structure, homologous structures may perform different functions in different organisms.
- The changes in function may have occurred as a result of adaptations to different environmental conditions or ecological niches.
4. Examples of homologous structures:
- The forelimbs of vertebrates, such as humans, cats, bats, and whales, are considered homologous structures.
- These forelimbs have similar bone structure, consisting of a humerus, radius, ulna, carpals, metacarpals, and phalanges.
- However, they have different functions, serving as arms, wings, or flippers in different species.
- Another example is the pentadactyl limb, which is a limb with five digits found in various vertebrates.
- This limb structure can be observed in the hands of humans, the wings of bats, and the flippers of dolphins.
- Despite these different functions, the underlying structure is similar.
5. Significance of homologous structures:
- Homologous structures provide evidence for common ancestry and evolution.
- By comparing the anatomical features of different organisms, scientists can infer relationships and evolutionary history.
In conclusion, homologous structures are organs or body parts with similar anatomical structures but may have different functions in different species. The presence of homologous structures supports the concept of common ancestry and evolution.
Explanation:
1. Definition of homologous structures:
- Homologous structures refer to organs or body parts that have similar structural features, indicating a common evolutionary origin.
- These structures may have been modified over time to perform different functions in different species.
2. Anatomical similarities:
- Homologous structures exhibit similarities in their basic structure, such as the arrangement of bones, muscles, or other tissues.
- These similarities suggest that these structures evolved from a common ancestor.
3. Different functions:
- Despite their similarities in structure, homologous structures may perform different functions in different organisms.
- The changes in function may have occurred as a result of adaptations to different environmental conditions or ecological niches.
4. Examples of homologous structures:
- The forelimbs of vertebrates, such as humans, cats, bats, and whales, are considered homologous structures.
- These forelimbs have similar bone structure, consisting of a humerus, radius, ulna, carpals, metacarpals, and phalanges.
- However, they have different functions, serving as arms, wings, or flippers in different species.
- Another example is the pentadactyl limb, which is a limb with five digits found in various vertebrates.
- This limb structure can be observed in the hands of humans, the wings of bats, and the flippers of dolphins.
- Despite these different functions, the underlying structure is similar.
5. Significance of homologous structures:
- Homologous structures provide evidence for common ancestry and evolution.
- By comparing the anatomical features of different organisms, scientists can infer relationships and evolutionary history.
In conclusion, homologous structures are organs or body parts with similar anatomical structures but may have different functions in different species. The presence of homologous structures supports the concept of common ancestry and evolution.
When a bar magnet is pushed towards the coil connected in series with a galvanometer, the pointer in the galvanometer G- a)shows deflection while bar is stationary
- b)oscillates
- c)shows deflection while bar is in motion
- d)does not move
Correct answer is option 'C'. Can you explain this answer?
When a bar magnet is pushed towards the coil connected in series with a galvanometer, the pointer in the galvanometer G
a)
shows deflection while bar is stationary
b)
oscillates
c)
shows deflection while bar is in motion
d)
does not move
|
Samridhi Bajaj answered |
Explanation:When bar is in motion then flux will changed hence current will be induced.
There are two stationary coils near each other. If current in coil-1 is changing with time, relationship of current in coil-2 to it's emf is described by- a)Alternating Inductance
- b)Self Inductance
- c)Variable Inductance
- d)Mutual Inductance.
Correct answer is option 'D'. Can you explain this answer?
There are two stationary coils near each other. If current in coil-1 is changing with time, relationship of current in coil-2 to it's emf is described by
a)
Alternating Inductance
b)
Self Inductance
c)
Variable Inductance
d)
Mutual Inductance.
|
Rishika Chauhan answered |
M is mutual inductance
Eddy Currents are- a)plasma currents
- b)induced solar currents that circulate throughout a river and are swirling .
- c)gaseous currents
- d)induced currents that circulate throughout the volume of a material similar to swirling eddies in a river.
Correct answer is option 'D'. Can you explain this answer?
Eddy Currents are
a)
plasma currents
b)
induced solar currents that circulate throughout a river and are swirling .
c)
gaseous currents
d)
induced currents that circulate throughout the volume of a material similar to swirling eddies in a river.
|
|
Raghav Yadav answered |
Explanation:Eddy currents (also called Foucault currents) are loops of electrical current induced within conductors by a changing magnetic field in the conductor, due to Faraday's law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field. By lenz's law an eddy current creates a magnetic field that opposes a change in the magnetic field that created it, and thus eddy currents react back on the source of the magnetic field.
Which of the following is true?- a)Wings of birds and insects are homologous organs.
- b)Human hands and wings of birds are analogous organs.
- c)Human hands and wings of bats are analogous organs.
- d)Flipper of seal and wings of birds are homologous organs.
Correct answer is option 'D'. Can you explain this answer?
Which of the following is true?
a)
Wings of birds and insects are homologous organs.
b)
Human hands and wings of birds are analogous organs.
c)
Human hands and wings of bats are analogous organs.
d)
Flipper of seal and wings of birds are homologous organs.
|
|
Suresh Iyer answered |
Flipper of seal and wing of birds are modified forelimbs, thus, have same fundamental structure but have different functions. Flippers are meant for swimming and wings are meant for flying. Therefore, these organs are homologous oroans.
Industrial melanism is an example of -- a)Mutation
- b)Natural selection
- c)Neo Darwinism
- d)Neo Lamarckism
Correct answer is option 'B'. Can you explain this answer?
Industrial melanism is an example of -
a)
Mutation
b)
Natural selection
c)
Neo Darwinism
d)
Neo Lamarckism
|
EduRev NEET answered |
Natural selection is the most widely accepted theory concerning the principal causal mechanism of evolutionary change profounded by Charles Darwin and Alfred Russel Wallace. It results from the differential reproduction (some members of a population produce abundant offspring, some only a few and still others none), one phenotype as compared with other phenotypes in the same population. This determines the relative share of different genotypes which individuals possess and propagate in a population. Industrial melanism supports evolution by natural selection. It is an adaptation where the moths living in the industrial areas developed melanin pigments to match their bodies to the tree trunks.
Which complex is likely to show optical activity- a)Trans-[CoCl2(NH3)4 ]+
- b)[Cr(H2O)6]3+
- c)Cis-[Co(NH3)2(en)2 ]3+
- d)Trans-[Co(NH3)2(en)2 ]3+
Correct answer is option 'C'. Can you explain this answer?
Which complex is likely to show optical activity
a)
Trans-[CoCl2(NH3)4 ]+
b)
[Cr(H2O)6]3+
c)
Cis-[Co(NH3)2(en)2 ]3+
d)
Trans-[Co(NH3)2(en)2 ]3+
|
|
Dishani Kulkarni answered |
Cis [Co(NH3)2(en)2]3+
No POS optically active rest compound has POS.
No POS optically active rest compound has POS.
Trioxalato aluminate (III) and tetrafluorido-borate (III) ions are respectively :- a)[Al(C2O4)3], [BF4]3-
- b)[Al(C2O4)3]3+ , [BF4]3+
- c)[Al(C2O4)3]3- , [BF4]-
- d)[Al(C2O4)3]2- , [BF4]2-
Correct answer is option 'C'. Can you explain this answer?
Trioxalato aluminate (III) and tetrafluorido-borate (III) ions are respectively :
a)
[Al(C2O4)3], [BF4]3-
b)
[Al(C2O4)3]3+ , [BF4]3+
c)
[Al(C2O4)3]3- , [BF4]-
d)
[Al(C2O4)3]2- , [BF4]2-
|
Maya Reddy answered |
Trioxalato aluminate (III) and tetrafluorido-borate (III) ions
- Trioxalato aluminate (III) ion: [Al(C2O4)3]^3-
- Tetrafluorido-borate (III) ion: [BF4]^-
Correct combination
The correct combination of these ions is option 'C', which is [Al(C2O4)3]^3- and [BF4]^-. This means that the trioxalato aluminate (III) ion has a 3- charge and the tetrafluorido-borate (III) ion has a 1- charge.
Explanation
- The trioxalato aluminate (III) ion consists of one aluminum ion (Al^3+) complexed with three oxalate ions (C2O4^2-) to balance the charge.
- The tetrafluorido-borate (III) ion consists of one boron ion (B^3+) complexed with four fluoride ions (F-) to balance the charge.
- Therefore, the correct notation for these ions is [Al(C2O4)3]^3- and [BF4]^-.
Kamla peddles a stationary bicycle the pedals of the bicycle are attached to a 100 turn coil of area 0.10m2. The coil rotates at half a revolution per second and it is placed in a uniform magnetic field of 0.02 T perpendicular to the axis of rotation of the coil. What is the maximum voltage generated in the coil?- a)0.628
- b)0.314
- c)0.714
- d)0.554
Correct answer is option 'A'. Can you explain this answer?
Kamla peddles a stationary bicycle the pedals of the bicycle are attached to a 100 turn coil of area 0.10m2. The coil rotates at half a revolution per second and it is placed in a uniform magnetic field of 0.02 T perpendicular to the axis of rotation of the coil. What is the maximum voltage generated in the coil?
a)
0.628
b)
0.314
c)
0.714
d)
0.554
|
Ishani Patel answered |
Maximum voltage
An AC generator consists of- a)A coil that can rotate in a permanent magnetic field and is provided with slip rings.
- b)A permanent magnet rotor and a stationary coil.
- c)Two stationary coils close to each other
- d)A stationary coil for emf and a movable coil fed with AC
Correct answer is option 'A'. Can you explain this answer?
An AC generator consists of
a)
A coil that can rotate in a permanent magnetic field and is provided with slip rings.
b)
A permanent magnet rotor and a stationary coil.
c)
Two stationary coils close to each other
d)
A stationary coil for emf and a movable coil fed with AC
|
Arshiya Choudhury answered |
Explanation:AC generators operate on the same fundamental principles of electromagnetic induction.The turning of a coil in a magnetic field produces motional emfs in both sides of the coil.A slip ring is a method of making an electrical connection through a rotating assembly. Formally, it is an electric transmission device that allows energy flow between two electrical rotating parts, such as in a motor.
The magnetic field between the Horizontal poles of an electromagnet is uniform at any time, but its magnitude is increasing at the rate of 0.020T/s.The area of a horizontal conducting loop in the magnetic field is 120cm2, and the total circuit resistance, including the meter, is 5Ω. Induced emf and the induced current in the circuit are- a)0.18 mV,0.048 mA
- b)0.22 mV,0.048 mA
- c)0.20 mV,0.048 mA
- d)0.24 mV,0.048 mA
Correct answer is option 'D'. Can you explain this answer?
The magnetic field between the Horizontal poles of an electromagnet is uniform at any time, but its magnitude is increasing at the rate of 0.020T/s.The area of a horizontal conducting loop in the magnetic field is 120cm2, and the total circuit resistance, including the meter, is 5Ω. Induced emf and the induced current in the circuit are
a)
0.18 mV,0.048 mA
b)
0.22 mV,0.048 mA
c)
0.20 mV,0.048 mA
d)
0.24 mV,0.048 mA
|
|
Anand Saha answered |
Magnetic Field
- The magnetic field between the horizontal poles of an electromagnet is uniform at any time.
- The magnitude of the magnetic field is increasing at a rate of 0.020 T/s.
Conducting Loop
- The area of the horizontal conducting loop in the magnetic field is 120 cm^2.
- The total circuit resistance, including the meter, is 5 Ω.
Induced EMF
- The induced EMF can be calculated using Faraday's law of electromagnetic induction.
- Faraday's law states that the induced EMF is equal to the rate of change of magnetic flux through the loop.
- The magnetic flux through the loop can be calculated by multiplying the magnetic field strength by the area of the loop.
- The rate of change of magnetic flux is equal to the rate of change of the magnetic field strength multiplied by the area of the loop.
- Substituting the given values, the rate of change of magnetic flux is (0.020 T/s) * (120 cm^2) = 2.4 T cm^2/s.
- To convert the magnetic flux to Weber (Wb), divide by 10,000: 2.4 T cm^2/s / 10,000 = 0.00024 Wb/s.
- Therefore, the induced EMF is 0.00024 V/s or 0.24 mV/s.
Induced Current
- The induced current can be calculated using Ohm's law, which states that the current is equal to the voltage divided by the resistance.
- Substituting the given values, the induced current is (0.24 mV/s) / (5 Ω) = 0.048 mA.
Conclusion
- The induced EMF in the circuit is 0.24 mV and the induced current is 0.048 mA.
- Therefore, the correct answer is option 'D', 0.24 mV, 0.048 mA.
- The magnetic field between the horizontal poles of an electromagnet is uniform at any time.
- The magnitude of the magnetic field is increasing at a rate of 0.020 T/s.
Conducting Loop
- The area of the horizontal conducting loop in the magnetic field is 120 cm^2.
- The total circuit resistance, including the meter, is 5 Ω.
Induced EMF
- The induced EMF can be calculated using Faraday's law of electromagnetic induction.
- Faraday's law states that the induced EMF is equal to the rate of change of magnetic flux through the loop.
- The magnetic flux through the loop can be calculated by multiplying the magnetic field strength by the area of the loop.
- The rate of change of magnetic flux is equal to the rate of change of the magnetic field strength multiplied by the area of the loop.
- Substituting the given values, the rate of change of magnetic flux is (0.020 T/s) * (120 cm^2) = 2.4 T cm^2/s.
- To convert the magnetic flux to Weber (Wb), divide by 10,000: 2.4 T cm^2/s / 10,000 = 0.00024 Wb/s.
- Therefore, the induced EMF is 0.00024 V/s or 0.24 mV/s.
Induced Current
- The induced current can be calculated using Ohm's law, which states that the current is equal to the voltage divided by the resistance.
- Substituting the given values, the induced current is (0.24 mV/s) / (5 Ω) = 0.048 mA.
Conclusion
- The induced EMF in the circuit is 0.24 mV and the induced current is 0.048 mA.
- Therefore, the correct answer is option 'D', 0.24 mV, 0.048 mA.
A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad s−1 about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of 0.5 T parallel to the axis exists everywhere. Emf developed between the centre and the ring is- a)120 V
- b)100 V .
- c)200 V
- d)150 V
Correct answer is option 'B'. Can you explain this answer?
A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad s−1 about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of 0.5 T parallel to the axis exists everywhere. Emf developed between the centre and the ring is
a)
120 V
b)
100 V .
c)
200 V
d)
150 V
|
Nishtha Bose answered |
On a cylindrical rod two coils are wound one above the other. What is the coefficient of mutual inductance if the inductance of each coil os 0.1H?- a)0.15H
- b)0.05H
- c)0.20H
- d)0.10H
Correct answer is option 'D'. Can you explain this answer?
On a cylindrical rod two coils are wound one above the other. What is the coefficient of mutual inductance if the inductance of each coil os 0.1H?
a)
0.15H
b)
0.05H
c)
0.20H
d)
0.10H
|
Rashi Bose answered |
As one coil is wound over the other so that coupling is tight i.e. k=1
Can you explain the answer of this question below:Predict the polarity of the capacitor in the situation described by fig.
- A:B’ will be positive with respect to plate ‘A’
- B:A’ will be positive with respect to plate ‘B’ .
- C:Not enough information
- D:No current induced
The answer is b.
Predict the polarity of the capacitor in the situation described by fig.
A:
B’ will be positive with respect to plate ‘A’
B:
A’ will be positive with respect to plate ‘B’ .
C:
Not enough information
D:
No current induced
|
Advait Ghosh answered |
Explanation:A will become positive with respect to B because current indused is in clockwise direction
A complex compound in which the oxidation number of a metal is zero is- a)K4 [Fe (CN)6]
- b)K3 [Fe (CN)6]
- c)[Ni (CO)4]
- d)[Pl (NH3 )4]Cl2
Correct answer is option 'C'. Can you explain this answer?
A complex compound in which the oxidation number of a metal is zero is
a)
K4 [Fe (CN)6]
b)
K3 [Fe (CN)6]
c)
[Ni (CO)4]
d)
[Pl (NH3 )4]Cl2
|
|
Sankar Singh answered |
A complex compound in which the oxidation number of metal is zero is [Ni(CO)4]. In this complex, the oxidation number of both metal and ligand is zero.
The oxidation number of metal in the complexes K4[Fe(CN)6], K3[Fe(CN)6] and [Pt(NH3)4]Cl2 are +2, +3 and +2 respectively.
The oxidation number of metal in the complexes K4[Fe(CN)6], K3[Fe(CN)6] and [Pt(NH3)4]Cl2 are +2, +3 and +2 respectively.
In which complex is the transition metal in zero oxidation state:- a)[Co(NH3)6Cl2]
- b)[Fe(H2O)6]SO4
- c)H[Co(CO)4]
- d)K4[Ni(CN)4]
Correct answer is option 'D'. Can you explain this answer?
In which complex is the transition metal in zero oxidation state:
a)
[Co(NH3)6Cl2]
b)
[Fe(H2O)6]SO4
c)
H[Co(CO)4]
d)
K4[Ni(CN)4]
|
Nilanjan Malik answered |
The answer to the question is option 'D' - K4[Ni(CN)4].
Explanation:
In order to determine the oxidation state of the transition metal in each complex, we need to analyze the ligands and their charge contributions.
a) [Co(NH3)6Cl2]:
- In this complex, we have six ammine (NH3) ligands and two chloride (Cl) ligands.
- Ammine is a neutral ligand, so it does not contribute any charge.
- Chloride is a negatively charged ligand, contributing a charge of -1 each. Since there are two chloride ligands, the total charge contribution is -2.
- Since the overall charge of the complex is 0, the oxidation state of the central transition metal (Co) must be +2 to balance the charge.
- Therefore, the transition metal in this complex is in the +2 oxidation state.
b) [Fe(H2O)6]SO4:
- In this complex, we have six water (H2O) ligands and a sulfate (SO4) ligand.
- Water is a neutral ligand, so it does not contribute any charge.
- Sulfate is a negatively charged ligand, contributing a charge of -2.
- Since the overall charge of the complex is 0, the oxidation state of the central transition metal (Fe) must be +2 to balance the charge.
- Therefore, the transition metal in this complex is in the +2 oxidation state.
c) H[Co(CO)4]:
- In this complex, we have four carbonyl (CO) ligands.
- Carbonyl is a neutral ligand, so it does not contribute any charge.
- Since there is no other ligand or counterion present in the complex, the overall charge of the complex is +1.
- Therefore, the oxidation state of the central transition metal (Co) must be -1 to balance the charge.
- Therefore, the transition metal in this complex is in the -1 oxidation state.
d) K4[Ni(CN)4]:
- In this complex, we have four cyanide (CN) ligands.
- Cyanide is a negatively charged ligand, contributing a charge of -1 each. Since there are four cyanide ligands, the total charge contribution is -4.
- Since the overall charge of the complex is -4 (as indicated by the K4 counterions), the oxidation state of the central transition metal (Ni) must be 0 to balance the charge.
- Therefore, the transition metal in this complex is in the 0 oxidation state.
Conclusion:
The transition metal in the complex K4[Ni(CN)4] is in the zero oxidation state.
Explanation:
In order to determine the oxidation state of the transition metal in each complex, we need to analyze the ligands and their charge contributions.
a) [Co(NH3)6Cl2]:
- In this complex, we have six ammine (NH3) ligands and two chloride (Cl) ligands.
- Ammine is a neutral ligand, so it does not contribute any charge.
- Chloride is a negatively charged ligand, contributing a charge of -1 each. Since there are two chloride ligands, the total charge contribution is -2.
- Since the overall charge of the complex is 0, the oxidation state of the central transition metal (Co) must be +2 to balance the charge.
- Therefore, the transition metal in this complex is in the +2 oxidation state.
b) [Fe(H2O)6]SO4:
- In this complex, we have six water (H2O) ligands and a sulfate (SO4) ligand.
- Water is a neutral ligand, so it does not contribute any charge.
- Sulfate is a negatively charged ligand, contributing a charge of -2.
- Since the overall charge of the complex is 0, the oxidation state of the central transition metal (Fe) must be +2 to balance the charge.
- Therefore, the transition metal in this complex is in the +2 oxidation state.
c) H[Co(CO)4]:
- In this complex, we have four carbonyl (CO) ligands.
- Carbonyl is a neutral ligand, so it does not contribute any charge.
- Since there is no other ligand or counterion present in the complex, the overall charge of the complex is +1.
- Therefore, the oxidation state of the central transition metal (Co) must be -1 to balance the charge.
- Therefore, the transition metal in this complex is in the -1 oxidation state.
d) K4[Ni(CN)4]:
- In this complex, we have four cyanide (CN) ligands.
- Cyanide is a negatively charged ligand, contributing a charge of -1 each. Since there are four cyanide ligands, the total charge contribution is -4.
- Since the overall charge of the complex is -4 (as indicated by the K4 counterions), the oxidation state of the central transition metal (Ni) must be 0 to balance the charge.
- Therefore, the transition metal in this complex is in the 0 oxidation state.
Conclusion:
The transition metal in the complex K4[Ni(CN)4] is in the zero oxidation state.
Type of isomerism exhibited by [Ir(OCN)2(H2O)3]- a)Hydrate isomerism
- b)Linkage isomerism
- c)Polymerization isomerism
- d)Both (B) and (C)
Correct answer is option 'D'. Can you explain this answer?
Type of isomerism exhibited by [Ir(OCN)2(H2O)3]
a)
Hydrate isomerism
b)
Linkage isomerism
c)
Polymerization isomerism
d)
Both (B) and (C)
|
|
Sankar Singh answered |
Explanation:
The given complex is [Ir(OCN)2(H2O)3]. It has two isomers, i.e., linkage and polymerization isomers.
Linkage Isomerism:
In linkage isomerism, the ligand can coordinate through a different atom of the same ligand to form a different compound. Here, the OCN^- ion can coordinate via nitrogen (N) or carbon (C).
- If OCN^- binds through N atom, it forms a linkage isomer.
- If OCN^- binds through C atom, it forms a normal isomer.
Hence, [Ir(OCN-N)2(H2O)3] and [Ir(OCN-C)2(H2O)3] are linkage isomers.
Polymerization Isomerism:
In polymerization isomerism, the ligand can have different bridging modes between two metal centers. Here, the OCN^- ion can act as a bridging ligand to form a polymer chain.
- If OCN^- bridges between two Ir centers, it forms a polymerization isomer.
- If OCN^- binds to only one Ir center, it forms a normal isomer.
Hence, [Ir(OCN)2(H2O)3] and [Ir(OCN)2(μ-OCN)(H2O)2] are polymerization isomers.
Conclusion:
Thus, the given complex exhibits both linkage and polymerization isomerism.
The given complex is [Ir(OCN)2(H2O)3]. It has two isomers, i.e., linkage and polymerization isomers.
Linkage Isomerism:
In linkage isomerism, the ligand can coordinate through a different atom of the same ligand to form a different compound. Here, the OCN^- ion can coordinate via nitrogen (N) or carbon (C).
- If OCN^- binds through N atom, it forms a linkage isomer.
- If OCN^- binds through C atom, it forms a normal isomer.
Hence, [Ir(OCN-N)2(H2O)3] and [Ir(OCN-C)2(H2O)3] are linkage isomers.
Polymerization Isomerism:
In polymerization isomerism, the ligand can have different bridging modes between two metal centers. Here, the OCN^- ion can act as a bridging ligand to form a polymer chain.
- If OCN^- bridges between two Ir centers, it forms a polymerization isomer.
- If OCN^- binds to only one Ir center, it forms a normal isomer.
Hence, [Ir(OCN)2(H2O)3] and [Ir(OCN)2(μ-OCN)(H2O)2] are polymerization isomers.
Conclusion:
Thus, the given complex exhibits both linkage and polymerization isomerism.
A metallic rod of 1 m length is rotated with a frequency of 50 rev/s about an axis passing through the centre point O. Other end of the metallic rod slides on a Metallic ring . A constant and uniform magnetic field of 2 T parallel to the axis is present everywhere. What is the emf between the centre and the metallic ring?
- a)220 V
- b)314 V .
- c)240 V
- d)300 V
Correct answer is option 'B'. Can you explain this answer?
A metallic rod of 1 m length is rotated with a frequency of 50 rev/s about an axis passing through the centre point O. Other end of the metallic rod slides on a Metallic ring . A constant and uniform magnetic field of 2 T parallel to the axis is present everywhere. What is the emf between the centre and the metallic ring?
a)
220 V
b)
314 V .
c)
240 V
d)
300 V
|
|
Nisha Kulkarni answered |
l = 1 m
= 314V
The magnetic field between the Horizontal poles of an electromagnet in is uniform at any time, but its magnitude is increasing at the rate of 0.020 T/s.The area of a loop made of perfect insulating material is 120cm2.This loop is kept horizontally in the magnetic field. Induced emf and the induced current in the circuit are- a)0.54 mV,zero
- b)0.84 mV,zero
- c)0.24 mV,zero
- d)0.14 mV,zero
Correct answer is option 'C'. Can you explain this answer?
The magnetic field between the Horizontal poles of an electromagnet in is uniform at any time, but its magnitude is increasing at the rate of 0.020 T/s.The area of a loop made of perfect insulating material is 120cm2.This loop is kept horizontally in the magnetic field. Induced emf and the induced current in the circuit are
a)
0.54 mV,zero
b)
0.84 mV,zero
c)
0.24 mV,zero
d)
0.14 mV,zero
|
|
Samridhi Bajaj answered |
e = Rate of change of magnetic field x area
=0.02×120×10−4=0.24mV
A population will not exist in Hardy-Weinberg equilibrium if- a)there are no mutations
- b)individuals mate selectively
- c)the population is large
- d)there is no migration
Correct answer is option 'B'. Can you explain this answer?
A population will not exist in Hardy-Weinberg equilibrium if
a)
there are no mutations
b)
individuals mate selectively
c)
the population is large
d)
there is no migration
|
Lead Academy answered |
The theory of Hardy- Weinberg equilibrium states that in the absence of disturbance on the level of genetic structure, a population’s existance will not continue. Thus mating should be in a random way.
In evolution, the studies can be made at molecular level. For example, the proteins present in the blood of man and ape are similar. The base sequence in nucleic acids and amino acids sequence in proteins of related organism is alike. These are the examples which are specifically referred to in- a)convergent evolution
- b)molecular analogy
- c)molecular homology
- d)homoplastic appearance
Correct answer is option 'C'. Can you explain this answer?
In evolution, the studies can be made at molecular level. For example, the proteins present in the blood of man and ape are similar. The base sequence in nucleic acids and amino acids sequence in proteins of related organism is alike. These are the examples which are specifically referred to in
a)
convergent evolution
b)
molecular analogy
c)
molecular homology
d)
homoplastic appearance
|
|
Siddharth Iyer answered |
The Concept of Molecular Homology
Molecular homology refers to the similarities in molecular structures, such as nucleic acids and proteins, that indicate a common evolutionary ancestor. This concept is fundamental in understanding evolutionary relationships among species.
Understanding Molecular Homology
- Shared Genetic Material:
- Organisms that share a common ancestor will often have similar DNA sequences. For example, humans and apes exhibit significant similarities in their DNA, which can be traced back to a shared evolutionary lineage.
- Protein Similarities:
- The amino acid sequences of proteins in related organisms also show remarkable similarities. This is evident in blood proteins, where humans and apes have closely related structures, reflecting their evolutionary connection.
Importance of Molecular Homology
- Evolutionary Relationships:
- Molecular homology provides evidence for the evolutionary relationships between species. The closer the genetic similarity, the more likely the organisms are related through common ancestry.
- Phylogenetic Analysis:
- Scientists utilize molecular homology in constructing phylogenetic trees, which visually represent the evolutionary pathways and connections among different species.
Distinction from Other Concepts
- Convergent Evolution:
- Unlike molecular homology, convergent evolution refers to unrelated species developing similar traits due to similar environmental pressures, not shared ancestry.
- Molecular Analogy and Homoplastic Appearance:
- These terms often refer to similar features arising independently in different species, rather than from a common ancestor, distinguishing them from molecular homology.
In summary, molecular homology plays a crucial role in the study of evolution, providing insights into the genetic and protein similarities that highlight the connections among various organisms.
Molecular homology refers to the similarities in molecular structures, such as nucleic acids and proteins, that indicate a common evolutionary ancestor. This concept is fundamental in understanding evolutionary relationships among species.
Understanding Molecular Homology
- Shared Genetic Material:
- Organisms that share a common ancestor will often have similar DNA sequences. For example, humans and apes exhibit significant similarities in their DNA, which can be traced back to a shared evolutionary lineage.
- Protein Similarities:
- The amino acid sequences of proteins in related organisms also show remarkable similarities. This is evident in blood proteins, where humans and apes have closely related structures, reflecting their evolutionary connection.
Importance of Molecular Homology
- Evolutionary Relationships:
- Molecular homology provides evidence for the evolutionary relationships between species. The closer the genetic similarity, the more likely the organisms are related through common ancestry.
- Phylogenetic Analysis:
- Scientists utilize molecular homology in constructing phylogenetic trees, which visually represent the evolutionary pathways and connections among different species.
Distinction from Other Concepts
- Convergent Evolution:
- Unlike molecular homology, convergent evolution refers to unrelated species developing similar traits due to similar environmental pressures, not shared ancestry.
- Molecular Analogy and Homoplastic Appearance:
- These terms often refer to similar features arising independently in different species, rather than from a common ancestor, distinguishing them from molecular homology.
In summary, molecular homology plays a crucial role in the study of evolution, providing insights into the genetic and protein similarities that highlight the connections among various organisms.
Consider the following statements, "According the Werner's theory. :(1) Ligands are connected to the metal ions by covalent bonds.(2) Secondary valencies have directional properties.(3) Secondary valencies are non-ionisable.(4) Secondary valencies are satisfied by either neutral or negative legands.Of these statements.- a)2, 3 and 4 are correct
- b)2 and 3 are correct
- c)1 and 3 are correct
- d)1, 2 and 4 are correct
Correct answer is option 'A'. Can you explain this answer?
Consider the following statements, "According the Werner's theory. :
(1) Ligands are connected to the metal ions by covalent bonds.
(2) Secondary valencies have directional properties.
(3) Secondary valencies are non-ionisable.
(4) Secondary valencies are satisfied by either neutral or negative legands.
Of these statements.
a)
2, 3 and 4 are correct
b)
2 and 3 are correct
c)
1 and 3 are correct
d)
1, 2 and 4 are correct
|
Amrita Sarkar answered |
Consider werner’s theroy
A complex of platinum, ammonia and chloride produces four ions per molecule in the solution. The structure consistent with the observation is :- a)[Pt(NH3)4]Cl4
- b)[Pt(NH3)2Cl4]
- c)[Pt(NH3)5Cl]Cl3
- d)[Pt(NH3)4Cl2]Cl 2
Correct answer is option 'C'. Can you explain this answer?
A complex of platinum, ammonia and chloride produces four ions per molecule in the solution. The structure consistent with the observation is :
a)
[Pt(NH3)4]Cl4
b)
[Pt(NH3)2Cl4]
c)
[Pt(NH3)5Cl]Cl3
d)
[Pt(NH3)4Cl2]Cl 2
|
Anu Basu answered |
[Pt(NH3)4]Cl4 → 5 ions
[Pt(NH3)2Cl4] → 0 ions
[Pt(NH3)4Cl2]Cl2 → 3 ions
Damping in galvanometers is based oUpdate Questionn- a)eddy currents generating currents in the core opposing the motion and bringing the coil to rest quickly.
- b)dash pot opposing the motion of the galvanometer needle
- c)needle movement being opposed by rubber touching the needle lightly
- d)needle movement being opposed by oil
Correct answer is option 'A'. Can you explain this answer?
Damping in galvanometers is based oUpdate Questionn
a)
eddy currents generating currents in the core opposing the motion and bringing the coil to rest quickly.
b)
dash pot opposing the motion of the galvanometer needle
c)
needle movement being opposed by rubber touching the needle lightly
d)
needle movement being opposed by oil
|
|
Nisha Pillai answered |
Explanation : The coil of galvanometer is wound on a light metal frame. When the coil and frame rotate in the field of the permanent magnet, the eddy current set up in the frame oppose the motion so that the coil returns to zero quickly.
If the polarity of induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, which conservation law is violated?- a)conservation of momentum
- b)conservation of charge
- c)conservation of energy.
- d)conservation of mass
Correct answer is option 'C'. Can you explain this answer?
If the polarity of induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, which conservation law is violated?
a)
conservation of momentum
b)
conservation of charge
c)
conservation of energy.
d)
conservation of mass
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Jhanvi Sengupta answered |
Conservation of Energy
The correct answer is option C, conservation of energy. This is because the law of conservation of energy states that energy cannot be created or destroyed, it can only be transferred or transformed from one form to another.
When an induced electromotive force (emf) is produced due to a change in magnetic flux, it creates a current in a circuit. The direction of this current depends on the direction of the change in magnetic flux and the polarity of the induced emf.
If the polarity of the induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, it means that the induced emf and the change in magnetic flux have the same direction. This indicates that the energy is being supplied to the circuit, rather than being conserved.
Explanation:
- Induced emf: When there is a change in the magnetic field through a coil of wire, an induced emf is produced. This can be due to various factors such as changing the magnetic field strength, changing the area of the coil, or changing the orientation of the coil with respect to the magnetic field.
- Change in magnetic flux: Magnetic flux is a measure of the number of magnetic field lines passing through a surface. When there is a change in the magnetic field or the area of the surface, the magnetic flux changes. This change in magnetic flux induces an emf in a coil of wire.
- Polarity of induced emf: The polarity of the induced emf depends on the direction of the change in magnetic flux. According to Faraday's law of electromagnetic induction, the induced emf is such that it opposes the change in magnetic flux. This is known as Lenz's law. However, in some cases, the induced emf can have the same direction as the change in magnetic flux.
- Conservation of energy: Energy is a fundamental concept in physics and is conserved in all physical processes. The law of conservation of energy states that energy cannot be created or destroyed, it can only be transferred or transformed from one form to another.
- Violation of conservation of energy: If the polarity of the induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, it means that energy is being supplied to the circuit. This violates the law of conservation of energy, as energy is not being conserved but rather being added to the system.
The correct answer is option C, conservation of energy. This is because the law of conservation of energy states that energy cannot be created or destroyed, it can only be transferred or transformed from one form to another.
When an induced electromotive force (emf) is produced due to a change in magnetic flux, it creates a current in a circuit. The direction of this current depends on the direction of the change in magnetic flux and the polarity of the induced emf.
If the polarity of the induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, it means that the induced emf and the change in magnetic flux have the same direction. This indicates that the energy is being supplied to the circuit, rather than being conserved.
Explanation:
- Induced emf: When there is a change in the magnetic field through a coil of wire, an induced emf is produced. This can be due to various factors such as changing the magnetic field strength, changing the area of the coil, or changing the orientation of the coil with respect to the magnetic field.
- Change in magnetic flux: Magnetic flux is a measure of the number of magnetic field lines passing through a surface. When there is a change in the magnetic field or the area of the surface, the magnetic flux changes. This change in magnetic flux induces an emf in a coil of wire.
- Polarity of induced emf: The polarity of the induced emf depends on the direction of the change in magnetic flux. According to Faraday's law of electromagnetic induction, the induced emf is such that it opposes the change in magnetic flux. This is known as Lenz's law. However, in some cases, the induced emf can have the same direction as the change in magnetic flux.
- Conservation of energy: Energy is a fundamental concept in physics and is conserved in all physical processes. The law of conservation of energy states that energy cannot be created or destroyed, it can only be transferred or transformed from one form to another.
- Violation of conservation of energy: If the polarity of the induced emf is such that it tends to produce a current which aids the change in magnetic flux that produced it, it means that energy is being supplied to the circuit. This violates the law of conservation of energy, as energy is not being conserved but rather being added to the system.
Coils C1 and C2 are stationary. C1 connected in series with one very small diwali bulb while C2 is connected to a battery .If the connection is suddenly snapped- a)the bulb glows momentarily.
- b)nothing happens to the bulb
- c)the bulb keeps glowing
- d)the bulb absorbs light
Correct answer is option 'A'. Can you explain this answer?
Coils C1 and C2 are stationary. C1 connected in series with one very small diwali bulb while C2 is connected to a battery .If the connection is suddenly snapped
a)
the bulb glows momentarily.
b)
nothing happens to the bulb
c)
the bulb keeps glowing
d)
the bulb absorbs light
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Surbhi Sengupta answered |
Explanation:Flux will be changed due to this current is induced momentarily
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