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All questions of JEE Advance 2019 for JEE Exam
A parallel plate capacitor of capacitance C has spacing d between two plates having area A. The region between the plates is filled with N dielectric layers, parallel to its plates, each with thickness 
The dielectric constant of the 
For a very large 
the capacitance C is 
The value of α will be ___________.
[∈0 is the permittivity of free space]
Correct answer is '1.00'. Can you explain this answer?
A parallel plate capacitor of capacitance C has spacing d between two plates having area A. The region between the plates is filled with N dielectric layers, parallel to its plates, each with thickness The dielectric constant of the For a very large the capacitance C is The value of α will be ___________.
[∈0 is the permittivity of free space]
The dielectric constant of the For a very large the capacitance C is The value of α will be ___________.[∈0 is the permittivity of free space]
|
Preeti Iyer answered |
Let S be the sample space of all 3 x 3 matrices with entries from the set {0, 1}. Let the events E1 and E2 be given by
E1 = {A ∈ S : det A = 0} and
E2 ={A ∈ S : sum of entries of A is 7}
If a matrix is chosen at random from S, then the conditional probability P(E1/E2) equals _____
Correct answer is '0.50'. Can you explain this answer?
Let S be the sample space of all 3 x 3 matrices with entries from the set {0, 1}. Let the events E1 and E2 be given by
E1 = {A ∈ S : det A = 0} and
E2 ={A ∈ S : sum of entries of A is 7}
If a matrix is chosen at random from S, then the conditional probability P(E1/E2) equals _____
E1 = {A ∈ S : det A = 0} and
E2 ={A ∈ S : sum of entries of A is 7}
If a matrix is chosen at random from S, then the conditional probability P(E1/E2) equals _____
|
Sahana Ahuja answered |
n(E2) = arrangement of 7, 1 and 2 or
both zero should be in a row or a column
(number of ways of arranging of (1, 0, 0) = 3 and arrangement of row = 3
total = 9 in same way for (1, 0, 0) for columns number of ways will be = 9 total ways = 18
both zero should be in a row or a column(number of ways of arranging of (1, 0, 0) = 3 and arrangement of row = 3total = 9 in same way for (1, 0, 0) for columns number of ways will be = 9 total ways = 18
On dissolving 0.5 g of a non-volatile non-ionic solute to 39 g of benzene, its vapour pressure decreases
from 650 mm Hg to 640 mm Hg. The depression of freezing point of benzene (in K) upon addition of the
solute is
(Given data: Molar mass and the molal freezing point depression constant of benzene are 78 g mol-1 and 5.12 K kg mol–1, respectively)
Correct answer is '1.02'. Can you explain this answer?
On dissolving 0.5 g of a non-volatile non-ionic solute to 39 g of benzene, its vapour pressure decreases
from 650 mm Hg to 640 mm Hg. The depression of freezing point of benzene (in K) upon addition of the
solute is
(Given data: Molar mass and the molal freezing point depression constant of benzene are 78 g mol-1 and 5.12 K kg mol–1, respectively)
from 650 mm Hg to 640 mm Hg. The depression of freezing point of benzene (in K) upon addition of the
solute is
(Given data: Molar mass and the molal freezing point depression constant of benzene are 78 g mol-1 and 5.12 K kg mol–1, respectively)
|
Ishani Menon answered |
-1
, respectively)
We can use the equation for the depression of freezing point:
ΔTf = Kf · m
where ΔTf is the change in freezing point, Kf is the molal freezing point depression constant, and m is the molality of the solute.
First, we need to find the molality of the solute:
molality = moles of solute / mass of solvent (in kg)
The mass of benzene is 39 g, which is 0.039 kg. The molar mass of the solute is not given, so we cannot find the moles directly. However, we are given the mass of the solute, which is 0.5 g. We can assume that the solute is non-ionic and non-volatile, which means that it does not affect the vapor pressure of benzene. Therefore, we can use Raoult's law to find the moles of benzene:
Ptotal = Pbenzene + Psolute
where Ptotal is the total vapor pressure, Pbenzene is the vapor pressure of pure benzene, and Psolute is the vapor pressure of the solute (which is assumed to be zero). We are given that Pbenzene decreases from 650 mm Hg to 640 mm Hg, so the change in vapor pressure is:
ΔPbenzene = Pbenzene - Pbenzene,pure = 650 mm Hg - 760 mm Hg = -110 mm Hg
We can use the following equation to find the moles of benzene:
nbenzene = (Pbenzene / Patm) · V / RT
where Patm is the atmospheric pressure (which we assume to be 1 atm), V is the volume of benzene (which we assume to be equal to its mass divided by its density, 0.879 g/mL), R is the gas constant, and T is the temperature (which is not given, but we assume to be room temperature, around 25°C or 298 K).
Plugging in the values, we get:
nbenzene = (650 mm Hg / 760 mm Hg) · (0.039 kg / 0.879 g/mL) / (0.0821 L·atm/mol·K · 298 K) ≈ 0.0014 mol
Since the solute is non-volatile, its mass will not affect the vapor pressure of benzene. Therefore, we can assume that the new mass of benzene is still 39 g. The mass of the solute is 0.5 g, so the total mass of the solution is 39.5 g. The molality of the solute is:
molality = moles of solute / mass of solvent (in kg) = 0.5 g / 0.039 kg ≈ 12.8 mol/kg
Now we can use the equation for the depression of freezing point:
ΔTf = Kf · m
Plugging in the values, we get:
ΔTf = 5.12 K kg/mol · 12.8 mol/kg ≈ 65.5 K
Therefore, the depression of freezing point of benzene upon addition of the solute is approximately 65.5 K.
, respectively)
We can use the equation for the depression of freezing point:
ΔTf = Kf · m
where ΔTf is the change in freezing point, Kf is the molal freezing point depression constant, and m is the molality of the solute.
First, we need to find the molality of the solute:
molality = moles of solute / mass of solvent (in kg)
The mass of benzene is 39 g, which is 0.039 kg. The molar mass of the solute is not given, so we cannot find the moles directly. However, we are given the mass of the solute, which is 0.5 g. We can assume that the solute is non-ionic and non-volatile, which means that it does not affect the vapor pressure of benzene. Therefore, we can use Raoult's law to find the moles of benzene:
Ptotal = Pbenzene + Psolute
where Ptotal is the total vapor pressure, Pbenzene is the vapor pressure of pure benzene, and Psolute is the vapor pressure of the solute (which is assumed to be zero). We are given that Pbenzene decreases from 650 mm Hg to 640 mm Hg, so the change in vapor pressure is:
ΔPbenzene = Pbenzene - Pbenzene,pure = 650 mm Hg - 760 mm Hg = -110 mm Hg
We can use the following equation to find the moles of benzene:
nbenzene = (Pbenzene / Patm) · V / RT
where Patm is the atmospheric pressure (which we assume to be 1 atm), V is the volume of benzene (which we assume to be equal to its mass divided by its density, 0.879 g/mL), R is the gas constant, and T is the temperature (which is not given, but we assume to be room temperature, around 25°C or 298 K).
Plugging in the values, we get:
nbenzene = (650 mm Hg / 760 mm Hg) · (0.039 kg / 0.879 g/mL) / (0.0821 L·atm/mol·K · 298 K) ≈ 0.0014 mol
Since the solute is non-volatile, its mass will not affect the vapor pressure of benzene. Therefore, we can assume that the new mass of benzene is still 39 g. The mass of the solute is 0.5 g, so the total mass of the solution is 39.5 g. The molality of the solute is:
molality = moles of solute / mass of solvent (in kg) = 0.5 g / 0.039 kg ≈ 12.8 mol/kg
Now we can use the equation for the depression of freezing point:
ΔTf = Kf · m
Plugging in the values, we get:
ΔTf = 5.12 K kg/mol · 12.8 mol/kg ≈ 65.5 K
Therefore, the depression of freezing point of benzene upon addition of the solute is approximately 65.5 K.
At 143 K, the reaction of XeF4 with O2F2 produces xenon compound Y. The total number of lone Pair(s) of electrons present on the whole molecule of Y is ………
Correct answer is '19.00'. Can you explain this answer?
At 143 K, the reaction of XeF4 with O2F2 produces xenon compound Y. The total number of lone Pair(s) of electrons present on the whole molecule of Y is ………
|
Sagar Kapoor answered |
To determine the number of lone pairs of electrons on the molecule of Y, we first need to write the balanced chemical equation for the reaction of XeF4 with O2F2:
XeF4 + 2O2F2 -> XeOF4 + 2OF2
From this equation, we can see that the product Y is XeOF4. To determine the number of lone pairs of electrons on XeOF4, we need to draw its Lewis structure.
First, we determine the total number of valence electrons in XeOF4:
Xe: 8 valence electrons
O: 6 valence electrons x 4 = 24 valence electrons
Total: 32 valence electrons
We then arrange the atoms in the molecule with Xe as the central atom:
F
|
O Xe O
|
F
Each bond in the molecule represents two electrons, so we can subtract 8 electrons for the four Xe-O bonds:
32 valence electrons - 8 electrons in Xe-O bonds = 24 electrons
We then distribute the remaining 24 electrons as lone pairs around the atoms:
F
|
O Xe O
| || |
e- LP e-
|
F
Each lone pair represents two electrons, so we can count the number of lone pairs to find the total number of lone pair electrons on the molecule:
4 lone pairs x 2 electrons per lone pair = 8 electrons
Therefore, the total number of lone pair electrons on the whole molecule of XeOF4 (product Y) is 8.
XeF4 + 2O2F2 -> XeOF4 + 2OF2
From this equation, we can see that the product Y is XeOF4. To determine the number of lone pairs of electrons on XeOF4, we need to draw its Lewis structure.
First, we determine the total number of valence electrons in XeOF4:
Xe: 8 valence electrons
O: 6 valence electrons x 4 = 24 valence electrons
Total: 32 valence electrons
We then arrange the atoms in the molecule with Xe as the central atom:
F
|
O Xe O
|
F
Each bond in the molecule represents two electrons, so we can subtract 8 electrons for the four Xe-O bonds:
32 valence electrons - 8 electrons in Xe-O bonds = 24 electrons
We then distribute the remaining 24 electrons as lone pairs around the atoms:
F
|
O Xe O
| || |
e- LP e-
|
F
Each lone pair represents two electrons, so we can count the number of lone pairs to find the total number of lone pair electrons on the molecule:
4 lone pairs x 2 electrons per lone pair = 8 electrons
Therefore, the total number of lone pair electrons on the whole molecule of XeOF4 (product Y) is 8.
A liquid at 30°C is poured very slowly into a Calorimeter that is at temperature of 110°C. The boiling temperature of the liquid is 80°C. It is found that the first 5 gm of the liquid completely evaporates. After pouring another 80 gm of the liquid the equilibrium temperature is found to be 50°C. The ratio of the Latent heat of the liquid to its specific heat will be _____________°C.[Neglect the heat exchange with surrounding]
Correct answer is '270.00'. Can you explain this answer?
A liquid at 30°C is poured very slowly into a Calorimeter that is at temperature of 110°C. The boiling temperature of the liquid is 80°C. It is found that the first 5 gm of the liquid completely evaporates. After pouring another 80 gm of the liquid the equilibrium temperature is found to be 50°C. The ratio of the Latent heat of the liquid to its specific heat will be _____________°C.[Neglect the heat exchange with surrounding]
|
Amrutha Chaudhary answered |
The mole fraction of urea in an aqueous urea solution containing 900 g of water is 0.05. If the density of the
solution is 1.2 g cm-3, the molarity of urea solution is______
(Given data: Molar masses of urea and water are 60 g mol-1 and 18 g mol-1, respectively)\
Correct answer is '2.98'. Can you explain this answer?
The mole fraction of urea in an aqueous urea solution containing 900 g of water is 0.05. If the density of the
solution is 1.2 g cm-3, the molarity of urea solution is______
(Given data: Molar masses of urea and water are 60 g mol-1 and 18 g mol-1, respectively)\
solution is 1.2 g cm-3, the molarity of urea solution is______
(Given data: Molar masses of urea and water are 60 g mol-1 and 18 g mol-1, respectively)\
|
Atharva Pillai answered |
Total number of cis N-Mn-Cl bond angles (that is, Mn – N and Mn – Cl bonds in cis positions) present in a
molecule of cis-[Mn(en)2Cl2] complex is______(en = NH2CH2CH2NH2)
Correct answer is '6.00'. Can you explain this answer?
Total number of cis N-Mn-Cl bond angles (that is, Mn – N and Mn – Cl bonds in cis positions) present in a
molecule of cis-[Mn(en)2Cl2] complex is______(en = NH2CH2CH2NH2)
molecule of cis-[Mn(en)2Cl2] complex is______(en = NH2CH2CH2NH2)
|
Athira Dasgupta answered |
There are two cis N-Mn-Cl bond angles in a tetrahedral complex with one nitrogen and two chloride ligands in cis position.
An optical bench has 1.5 m long scale having four equal divisions in each cm. While measuring the focal length of a convex lens, the lens is kept at 75 cm mark of the scale and the object pin is kept at 45 cm mark.The image of the object pin on the other side of the lens overlaps with image pin that is kept at 135 cm mark. In this experiment, the percentage error in the measurement of the focal length of the lens is_______.
Correct answer is '1.39'. Can you explain this answer?
An optical bench has 1.5 m long scale having four equal divisions in each cm. While measuring the focal length of a convex lens, the lens is kept at 75 cm mark of the scale and the object pin is kept at 45 cm mark.The image of the object pin on the other side of the lens overlaps with image pin that is kept at 135 cm mark. In this experiment, the percentage error in the measurement of the focal length of the lens is_______.
|
Sarthak Khanna answered |
Fusion of MnO2 with KOH in presence of O2 produces a salt W. Alkaline solution of W upon electrolyticoxidation yields another salt X. The manganese containing ions present in W and X, respectively, are Y andZ. Correct statement(s) is(are)- a)In aqueous acidic solution, Y undergoes disproportionation reaction to give Z and MnO2
- b)In both Y and Z, π-bonding occurs between p-orbitals of oxygen and d-orbitals of manganese
- c)Y is diamagnetic in nature while Z is paramagnetic
- d)Both Y and Z are coloured and have tetrahedral shape
Correct answer is option 'A,B,D'. Can you explain this answer?
Fusion of MnO2 with KOH in presence of O2 produces a salt W. Alkaline solution of W upon electrolyticoxidation yields another salt X. The manganese containing ions present in W and X, respectively, are Y andZ. Correct statement(s) is(are)
a)
In aqueous acidic solution, Y undergoes disproportionation reaction to give Z and MnO2
b)
In both Y and Z, π-bonding occurs between p-orbitals of oxygen and d-orbitals of manganese
c)
Y is diamagnetic in nature while Z is paramagnetic
d)
Both Y and Z are coloured and have tetrahedral shape
|
Amrita Sharma answered |
Molar conductivity (∧m) of aqueous solution of sodium stearate, which behaves as a strong electrolyte, isrecorded at varying concentrations (c) of sodium stearate. Which one of the following plots provides thecorrect representation of micelle formation in the solution?
(critical micelle concentration (CMC) is marked with an arrow in the figures- a)
- b)
- c)
- d)
Correct answer is option 'B'. Can you explain this answer?
Molar conductivity (∧m) of aqueous solution of sodium stearate, which behaves as a strong electrolyte, isrecorded at varying concentrations (c) of sodium stearate. Which one of the following plots provides thecorrect representation of micelle formation in the solution?
(critical micelle concentration (CMC) is marked with an arrow in the figures
(critical micelle concentration (CMC) is marked with an arrow in the figures
a)
b)
c)
d)
|
Anjali Sharma answered |
As the concentration of sodium stearate increases beyond
, stearate ions get clubbed together and form micelles. This abruptly causes the concentration of the current carrier anions to decreases. This is reflected by the sharp change in
at
, followed by a greater rate of decrease of
with underoot
Each of the following options contains a set of four molecules, Identify the option(s) where all four molecules possess permanent dipole moment at room temperature.- a)SO2, C6H5Cl, H2Se, BrF5
- b)BeCl2, CO2, BCl3, CHCl3
- c)BF3, O3, SF6, XeF6
- d)NO2, NH3, POCl3, CH3Cl
Correct answer is option 'A,D'. Can you explain this answer?
Each of the following options contains a set of four molecules, Identify the option(s) where all four molecules possess permanent dipole moment at room temperature.
a)
SO2, C6H5Cl, H2Se, BrF5
b)
BeCl2, CO2, BCl3, CHCl3
c)
BF3, O3, SF6, XeF6
d)
NO2, NH3, POCl3, CH3Cl
|
Suyash Mehra answered |
Explanation:
Option A: SO2, C6H5Cl, H2Se, BrF5
- SO2 (Sulfur dioxide), C6H5Cl (Chlorobenzene), H2Se (Hydrogen selenide), and BrF5 (Bromine pentafluoride) all have permanent dipole moments due to the presence of polar bonds in their molecular structures. These molecules are asymmetrical and have a net dipole moment, making them polar.
Option D: NO2, NH3, POCl3, CH3Cl
- NO2 (Nitrogen dioxide), NH3 (Ammonia), POCl3 (Phosphoryl chloride), and CH3Cl (Chloromethane) also exhibit permanent dipole moments at room temperature. These molecules have polar bonds and are asymmetrical, resulting in a non-zero net dipole moment.
Therefore, options A and D contain sets of molecules that possess permanent dipole moments at room temperature.
Three glass cylinders of equal height H = 30 cm and same refractive index n = 1.5 are placed on a horizontal surface as shown in figure. Cylinder I has a flat top, cylinder II has a convex top and cylinder III has a concave top. The radii of curvature of the two curved tops are same (R = 3m). If H1, H2 and H3 are the apparent depths of a point X on the bottom of the three cylinders, respectively, the correct statement(s) is/are:
- a)H2 > H1
- b)H2 > H3
- c)H3 > H1
- d)0.8 cm < (H2 – H1) < 0.9 cm
Correct answer is option 'A,B'. Can you explain this answer?
Three glass cylinders of equal height H = 30 cm and same refractive index n = 1.5 are placed on a horizontal surface as shown in figure. Cylinder I has a flat top, cylinder II has a convex top and cylinder III has a concave top. The radii of curvature of the two curved tops are same (R = 3m). If H1, H2 and H3 are the apparent depths of a point X on the bottom of the three cylinders, respectively, the correct statement(s) is/are:
a)
H2 > H1
b)
H2 > H3
c)
H3 > H1
d)
0.8 cm < (H2 – H1) < 0.9 cm
|
Krish Ghoshal answered |
Answer the following by appropriately matching the lists based on the information given in the paragraphList-I includes starting materials and reagents of selected chemical reactions. List-II gives structures of
compounds that may be formed as intermediate products and/or final products from the reactions of List-I.
Q. Which of the following options has the correct combination considering List-I and List-II?Options- a)(IV), (Q), (U)
- b)(IV), (Q), (R)
- c)(III), (S), (R)
- d)(III), (T), (U)
Correct answer is option 'B'. Can you explain this answer?
Answer the following by appropriately matching the lists based on the information given in the paragraph
List-I includes starting materials and reagents of selected chemical reactions. List-II gives structures of
compounds that may be formed as intermediate products and/or final products from the reactions of List-I.
compounds that may be formed as intermediate products and/or final products from the reactions of List-I.
Q. Which of the following options has the correct combination considering List-I and List-II?Options
a)
(IV), (Q), (U)
b)
(IV), (Q), (R)
c)
(III), (S), (R)
d)
(III), (T), (U)
|
Dipika Choudhury answered |
A line y = mx + 1 intersects the circle (x – 3)2 + (y + 2)2 = 25 at the points P and Q. If the midpoint of the
line segment PQ has x-coordinate 
then which one of the following options is correct?- a)
- b)
- c)
- d)
Correct answer is option 'C'. Can you explain this answer?
A line y = mx + 1 intersects the circle (x – 3)2 + (y + 2)2 = 25 at the points P and Q. If the midpoint of the
line segment PQ has x-coordinate then which one of the following options is correct?
line segment PQ has x-coordinate
then which one of the following options is correct?a)
b)
c)
d)
|
Ruchi Yadav answered |
⇒ m2 – 5m + 6 = 0
⇒ m = 2, 3
A perfectly reflecting mirror of mass M mounted on a spring constitutes a spring-mass system of angular frequency Ω such that 4πMΩ/h =1024 m-2 with h as Planck’s constant. N photons of wavelength λ = 8π * 10-6 m strike the mirror simultaneously at normal incidence such that the mirror gets displaced by 1 µm. If the value of N is x * 1012 then the value of x is _________. [Consider the spring as massless]
Correct answer is '1.00'. Can you explain this answer?
A perfectly reflecting mirror of mass M mounted on a spring constitutes a spring-mass system of angular frequency Ω such that 4πMΩ/h =1024 m-2 with h as Planck’s constant. N photons of wavelength λ = 8π * 10-6 m strike the mirror simultaneously at normal incidence such that the mirror gets displaced by 1 µm. If the value of N is x * 1012 then the value of x is _________. [Consider the spring as massless]
|
|
Krish Ghoshal answered |
A charged shell of radius R carries a total charge Q. Given 
as the flux of electric field through a closed cylindrical surface of height h, radius r and with its center same as that of the shell. Here, center of thecylinder is a point on the axis of the cylinder which is equidistant from its top and bottom surfaces. Whichof the following option(s) is/are correct?
[ε0 is permittivity of free space]- a)If h < 8R/5 and r = 3R/5 then
= 0 - b)
- c)
- d)
Correct answer is option 'A,B,D'. Can you explain this answer?
A charged shell of radius R carries a total charge Q. Given as the flux of electric field through a closed cylindrical surface of height h, radius r and with its center same as that of the shell. Here, center of thecylinder is a point on the axis of the cylinder which is equidistant from its top and bottom surfaces. Whichof the following option(s) is/are correct?
[ε0 is permittivity of free space]
as the flux of electric field through a closed cylindrical surface of height h, radius r and with its center same as that of the shell. Here, center of thecylinder is a point on the axis of the cylinder which is equidistant from its top and bottom surfaces. Whichof the following option(s) is/are correct?[ε0 is permittivity of free space]
a)
If h < 8R/5 and r = 3R/5 then = 0
= 0b)
c)
d)
|
Mehul Chavan answered |
A 10 cm long perfectly conducting wire PQ is moving with a velocity 1 cm/s on a pair of horizontal rails of zero resistance. One side of the rails is connected to an inductor L = 1 mH and a resistance R = 1Ω as shown in the figure. The horizontal rails, L and R lie in the same plane with a uniform magnetic field B = 1 T perpendicular to the plane. If the key S is closed at certain instant, the current in the circuit after 1 millisecond is x * 10-3 A, where the value of x is ________[Assume the velocity of wire PQ remains constant (1 cm/s) after key S is closed. Given: e-1 = 0.37, where e
is base of the natural logarithm]
Correct answer is '0.63'. Can you explain this answer?
A 10 cm long perfectly conducting wire PQ is moving with a velocity 1 cm/s on a pair of horizontal rails of zero resistance. One side of the rails is connected to an inductor L = 1 mH and a resistance R = 1Ω as shown in the figure. The horizontal rails, L and R lie in the same plane with a uniform magnetic field B = 1 T perpendicular to the plane. If the key S is closed at certain instant, the current in the circuit after 1 millisecond is x * 10-3 A, where the value of x is ________
[Assume the velocity of wire PQ remains constant (1 cm/s) after key S is closed. Given: e-1 = 0.37, where e
is base of the natural logarithm]
is base of the natural logarithm]
|
Sanaya Menon answered |
In a radioactive sample 
K nuclei either decay into stable 
Ca nuclei with decay constant 4.5x10-10 per year or into stable 
Ar nuclei with decay constant 0.5x10-10 per year. Given that in this sample all the stable 
Ca and 
Ar nuclei are produced by the 
K nuclei only. In time t x 109 years, if the ratio of the sum of stable 
Ca and 
Ar nuclei to the radioactive 
K nuclei is 99, the value of t will be
[Given : ln10 = 2.3]- a)1.15
- b)4.6
- c)9.2
- d)2.3
Correct answer is option 'C'. Can you explain this answer?
In a radioactive sample K nuclei either decay into stable Ca nuclei with decay constant 4.5x10-10 per year or into stable Ar nuclei with decay constant 0.5x10-10 per year. Given that in this sample all the stable Ca and Ar nuclei are produced by the K nuclei only. In time t x 109 years, if the ratio of the sum of stable Ca and Ar nuclei to the radioactive K nuclei is 99, the value of t will be
[Given : ln10 = 2.3]
K nuclei either decay into stable Ca nuclei with decay constant 4.5x10-10 per year or into stable Ar nuclei with decay constant 0.5x10-10 per year. Given that in this sample all the stable Ca and Ar nuclei are produced by the K nuclei only. In time t x 109 years, if the ratio of the sum of stable Ca and Ar nuclei to the radioactive K nuclei is 99, the value of t will be[Given : ln10 = 2.3]
a)
1.15
b)
4.6
c)
9.2
d)
2.3
|
Pranav Pillai answered |
So equivalent decay constant = 
For the following reaction, the equilibrium constant 
When equal volumes of 0.06 M Fe2+(aq) and 0.2 M S2–(aq) solutions are mixed, the equilibrium concentration of Fe2+(aq) is found to be Y x 10–17 M. The value of Y is ……… .
Correct answer is '8.93'. Can you explain this answer?
For the following reaction, the equilibrium constant
When equal volumes of 0.06 M Fe2+(aq) and 0.2 M S2–(aq) solutions are mixed, the equilibrium concentration of Fe2+(aq) is found to be Y x 10–17 M. The value of Y is ……… .
When equal volumes of 0.06 M Fe2+(aq) and 0.2 M S2–(aq) solutions are mixed, the equilibrium concentration of Fe2+(aq) is found to be Y x 10–17 M. The value of Y is ……… .
|
Saikat Dasgupta answered |
A small particle of mass m moving inside a heavy,hollow and straight tube along the tube axis undergoes elastic collision at two ends. The tube has no friction and it is closed at one end by a flat surface while the other end is fitted with a heavy movable flat piston as shown in figure. When the distance of the piston from closed end is L = L0 the particle speed is v = v0. The piston is moved inward at a very low speed V such that 
, where dL is the infinitesimal displacement of the piston. which of the following statement(s) is/are correct?
- a)The particle’s kinetic energy increases by a factor of 4 when the piston is moved inward from L0 to 1/2L0
- b)After each collision with the piston, the particle speed increases by 2V.
- c)If the piston moves inward by dL, the particle speed increases by
- d)The rate at which the particle strikes the piston is v/L
Correct answer is option 'A,B'. Can you explain this answer?
A small particle of mass m moving inside a heavy,hollow and straight tube along the tube axis undergoes elastic collision at two ends. The tube has no friction and it is closed at one end by a flat surface while the other end is fitted with a heavy movable flat piston as shown in figure. When the distance of the piston from closed end is L = L0 the particle speed is v = v0. The piston is moved inward at a very low speed V such that , where dL is the infinitesimal displacement of the piston. which of the following statement(s) is/are correct?
, where dL is the infinitesimal displacement of the piston. which of the following statement(s) is/are correct?a)
The particle’s kinetic energy increases by a factor of 4 when the piston is moved inward from L0 to 1/2L0
b)
After each collision with the piston, the particle speed increases by 2V.
c)
If the piston moves inward by dL, the particle speed increases by
d)
The rate at which the particle strikes the piston is v/L
|
|
Sarthak Khanna answered |
The rate of the reaction for [A] = 0.15 mol dm–3, [B] = 0.25 mol dm–3 and [C] = 0.15 mol dm–3 is found to be Y x 10–5 mol dm–3s–1. The value of Y is ………..
Correct answer is '6.75'. Can you explain this answer?
The rate of the reaction for [A] = 0.15 mol dm–3, [B] = 0.25 mol dm–3 and [C] = 0.15 mol dm–3 is found to be Y x 10–5 mol dm–3s–1. The value of Y is ………..
|
|
Mehul Chavan answered |
By exp. No. 1 & 2 y = 0
By exp. No. 1 & 3 z = 1
By exp. No. 1 & 4 x = 1
= 3x10-3 x 0.15x1x 0.15
Q. If the process on one mole of monatomic ideal gas is as shown in the TV-diagram with P0V0 = 1/3 RT0, the correct match is,
- a)I → P, II → T, III → Q, IV → T
- b)I → S, II → T, III → Q, IV → U
- c)I → P, II → R, III → T, IV → S
- d)I → P, II → R, III → T, IV → P
Correct answer is option 'D'. Can you explain this answer?
Q. If the process on one mole of monatomic ideal gas is as shown in the TV-diagram with P0V0 = 1/3 RT0, the correct match is,
a)
I → P, II → T, III → Q, IV → T
b)
I → S, II → T, III → Q, IV → U
c)
I → P, II → R, III → T, IV → S
d)
I → P, II → R, III → T, IV → P
|
Devansh Joshi answered |
Answer the following by appropriately matching the lists based on the information given in the paragraph
Q. Which of the following options has the correct combination considering List-I and List-II?Options- a)(III), (P)
- b)(IV), (U)
- c)(III), (S)
- d)(IV), (Q)
Correct answer is option 'A'. Can you explain this answer?
Answer the following by appropriately matching the lists based on the information given in the paragraph
Q. Which of the following options has the correct combination considering List-I and List-II?Options
a)
(III), (P)
b)
(IV), (U)
c)
(III), (S)
d)
(IV), (Q)
|
Gayatri Patel answered |
Which of the following statement(s) is(are) correct regarding the root mean square speed 
and average translational kinetic energy 
of a molecule in a gas at equilibrium ?- a)εav at a given temperature does not depend on its molecular mass
- b)Urms is doubled when its temperature is increased four times
- c)εav is doubled when its temperature is increased four times
- d)Urms is inversely proportional to the square root of its molecular mass
Correct answer is option 'A,B,D'. Can you explain this answer?
Which of the following statement(s) is(are) correct regarding the root mean square speed and average translational kinetic energy of a molecule in a gas at equilibrium ?
and average translational kinetic energy of a molecule in a gas at equilibrium ?a)
εav at a given temperature does not depend on its molecular mass
b)
Urms is doubled when its temperature is increased four times
c)
εav is doubled when its temperature is increased four times
d)
Urms is inversely proportional to the square root of its molecular mass
|
|
Sahana Ahuja answered |
Eav does not depend on its molecular mass but depends upon absolute temperature.
Consider a spherical gaseous cloud of mass density ρ(r) in free space where r is the radial distance from its center. The gaseous cloud is made of particles of equal mass m moving in circular orbits about the common center with the same kinetic energy K. The force acting on the particles is their mutual gravitational force. If ρ(r) is constant in time, the particle number density n(r) = ρ(r)/m is
[G is universal gravitational constant]- a)
- b)
- c)
- d)
Correct answer is option 'B'. Can you explain this answer?
Consider a spherical gaseous cloud of mass density ρ(r) in free space where r is the radial distance from its center. The gaseous cloud is made of particles of equal mass m moving in circular orbits about the common center with the same kinetic energy K. The force acting on the particles is their mutual gravitational force. If ρ(r) is constant in time, the particle number density n(r) = ρ(r)/m is
[G is universal gravitational constant]
[G is universal gravitational constant]
a)
b)
c)
d)
|
|
Mehul Chavan answered |
so from equation (i)
where x and y are in meter and 
The work done on the particle by this force 
will be _______ Joule.
There are three bags B1, B2 and B3. The bag B1 contains 5 red and 5 green balls, B2 contains 3 red and 5
green balls and B3 contains 5 red and 3 green balls. Bags B1, B2 and B3 have probabilities 
respectively of being chosen. A bag is selected at random and a ball is chosen at random from the bag. Then which of the following options is/are correct?- a)Probability that the chosen ball is green equals
- b)Probability that the chosen ball is green, given that the selected bag is B3, equals
- c)Probability that the selected bag is B3 and the chosen ball is green equals
- d)Probability that the selected bag is B3, given that the chosen ball is green, equals
Correct answer is option 'A,B'. Can you explain this answer?
There are three bags B1, B2 and B3. The bag B1 contains 5 red and 5 green balls, B2 contains 3 red and 5
green balls and B3 contains 5 red and 3 green balls. Bags B1, B2 and B3 have probabilities respectively of being chosen. A bag is selected at random and a ball is chosen at random from the bag. Then which of the following options is/are correct?
green balls and B3 contains 5 red and 3 green balls. Bags B1, B2 and B3 have probabilities
respectively of being chosen. A bag is selected at random and a ball is chosen at random from the bag. Then which of the following options is/are correct?a)
Probability that the chosen ball is green equals
b)
Probability that the chosen ball is green, given that the selected bag is B3, equals
c)
Probability that the selected bag is B3 and the chosen ball is green equals
d)
Probability that the selected bag is B3, given that the chosen ball is green, equals
|
Manisha Mehta answered |
Let the point B be the reflection of the point A(2, 3) with respect to line 8x – 6y – 23 = 0. Let 
be circles of radii 2 and 1 with centres A and B respectively. Let T be a common tangent to the circles 
and 
such that both the circles are on the same side of T. If C is the point of intersection of T and the line passing through A and B, then the length of the line segment AC is _____
Correct answer is '10.00'. Can you explain this answer?
Let the point B be the reflection of the point A(2, 3) with respect to line 8x – 6y – 23 = 0. Let be circles of radii 2 and 1 with centres A and B respectively. Let T be a common tangent to the circles and such that both the circles are on the same side of T. If C is the point of intersection of T and the line passing through A and B, then the length of the line segment AC is _____
be circles of radii 2 and 1 with centres A and B respectively. Let T be a common tangent to the circles and such that both the circles are on the same side of T. If C is the point of intersection of T and the line passing through A and B, then the length of the line segment AC is _____|
|
Ruchi Yadav answered |
now ΔAPC and BQC are similarly
Let L1 and L2 denote the lines 
and 
respectively. If L3 is a line which is perpendicular to both L1 and L2 and cuts both of them, then which of the following options describe (s) L3?- a)
- b)
- c)
- d)
Correct answer is option 'A,B,C'. Can you explain this answer?
Let L1 and L2 denote the lines and respectively. If L3 is a line which is perpendicular to both L1 and L2 and cuts both of them, then which of the following options describe (s) L3?
and respectively. If L3 is a line which is perpendicular to both L1 and L2 and cuts both of them, then which of the following options describe (s) L3?a)
b)
c)
d)
|
|
Disha Tiwari answered |
L1 & L2 are skew lines The direction ratios of line AB which is perpendicular to L1 and L2 will be
Hence direction ratios of AB will be (2, 2, –1) direction ratios of AB proportional to (2, 2, –1)
solving (i) (ii) & (iii) we get λ = 1/9
Equation of line L3 (A, B) passing through A
option (A) correct Equation of line L3 passing through B
Option (C) is correct, option (B) also satisfy
A ball is thrown from ground at an angle θ with horizontal and with an initial speed u0. For the resulting
projectile motion, the magnitude of average velocity of the ball up to the point when it hits the ground for
the first time is V1. After hitting the ground, the ball rebounds at the same angle θ but with a reduced speed
of u0/α. Its motion continues for a long time as shown in figure. If the magnitude of average velocity of the
ball for entire duration of motion is 0.8 V1, the value of α is________.
Correct answer is '4.00'. Can you explain this answer?
A ball is thrown from ground at an angle θ with horizontal and with an initial speed u0. For the resulting
projectile motion, the magnitude of average velocity of the ball up to the point when it hits the ground for
the first time is V1. After hitting the ground, the ball rebounds at the same angle θ but with a reduced speed
of u0/α. Its motion continues for a long time as shown in figure. If the magnitude of average velocity of the
ball for entire duration of motion is 0.8 V1, the value of α is________.
projectile motion, the magnitude of average velocity of the ball up to the point when it hits the ground for
the first time is V1. After hitting the ground, the ball rebounds at the same angle θ but with a reduced speed
of u0/α. Its motion continues for a long time as shown in figure. If the magnitude of average velocity of the
ball for entire duration of motion is 0.8 V1, the value of α is________.
|
Ipsita Sen answered |
Answer the following by appropriately matching the lists based on the information given in the paragraphList-I includes starting materials and reagents of selected chemical reactions. List-II gives structures ofcompounds that may be formed as intermediate products and/or final products from the reactions of List-I.
Q. Which of the following options has the correct combination considering List-I and List-II?Options - a)(II), (P), (S), (T)
- b)(II), (P), (S), (U)
- c)(I), (S), (Q), (R)
- d)(I), (Q), (T), (U)
Correct answer is option 'B'. Can you explain this answer?
Answer the following by appropriately matching the lists based on the information given in the paragraph
List-I includes starting materials and reagents of selected chemical reactions. List-II gives structures ofcompounds that may be formed as intermediate products and/or final products from the reactions of List-I.
Q. Which of the following options has the correct combination considering List-I and List-II?Options
a)
(II), (P), (S), (T)
b)
(II), (P), (S), (U)
c)
(I), (S), (Q), (R)
d)
(I), (Q), (T), (U)
|
Nishanth Verma answered |
The decomposition reaction 
is started in a closed cylinder under
isothermal isochoric condition at an initial pressure of 1 atm. After Y × 103 s, the pressure inside the
cylinder is found to be 1.45 atm. If the rate constant of the reaction is 5 × 10-4 s-1, assuming ideal gas
behaviour, the value of Y is_______
Correct answer is '2.30'. Can you explain this answer?
The decomposition reaction is started in a closed cylinder under
isothermal isochoric condition at an initial pressure of 1 atm. After Y × 103 s, the pressure inside the
cylinder is found to be 1.45 atm. If the rate constant of the reaction is 5 × 10-4 s-1, assuming ideal gas
behaviour, the value of Y is_______
is started in a closed cylinder underisothermal isochoric condition at an initial pressure of 1 atm. After Y × 103 s, the pressure inside the
cylinder is found to be 1.45 atm. If the rate constant of the reaction is 5 × 10-4 s-1, assuming ideal gas
behaviour, the value of Y is_______
|
Athul Patel answered |
denotes the transpose of the matrix Pk. Then which of the following options is/are correct?
Let 
denote a curve y = y(x) which is in the first quadrant and let the point (1, 0) lie on it. Let the tangent to 
at a point P intersect the y-axis at YP. If PYP has length l for each point P on 
, then which of the following option is/are correct?- a)
- b)
- c)
- d)
Correct answer is option 'A,B'. Can you explain this answer?
Let denote a curve y = y(x) which is in the first quadrant and let the point (1, 0) lie on it. Let the tangent to at a point P intersect the y-axis at YP. If PYP has length l for each point P on , then which of the following option is/are correct?
denote a curve y = y(x) which is in the first quadrant and let the point (1, 0) lie on it. Let the tangent to at a point P intersect the y-axis at YP. If PYP has length l for each point P on , then which of the following option is/are correct?a)
b)
c)
d)
|
|
Amrita Sharma answered |
Equation tangent
As curve y = y(x) lies in the first quadrant so option A and B will only satisfy. so AB are correct.
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