An em wave is propagating in a medium with a velocity The instantaneous oscillating electric field of this em wave is along +y axis. Then the direction of oscillating magnetic field of the em wave will be along :-
The refractive index of the material of a prism is √2 and the angle of the prism is 30°. One of thetwo refracting surfaces of the prism is made a mirrorinwards , by silver coat ing. A b eam ofmonochromatic light entering the prism from theother face will retrace its path (after reflection fromthe silvered surface) if its angle of incidence on the prism is :-
The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance :-
Energy stored in the inductor
Energy stored in the inductor
An object is placed at a distance of 40 cm froma concave mirror of focal length 15 cm. If the objectis displaced through a distance of 20 cm towardsthe mirror, the displacement of the image will be:-
In the combination of the following gates the output Y can be written in terms of inputs A and B as :-
In the circuit shown in the figure, the input voltage Vi is 20 V, VBE = 0 and VCE = 0. The values of IB, IC and β are given by :-
In a p-n junction diode, change in temperature due to heating :-
Affects the overall V - I characteristic of p-n junction.
On heating, a number of electron - hole pairs increase, so overall resistance of diode will change.
Hence, forward biasing and reversed biasing both are changed.
A small sphere of radius 'r' falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to :-
A sample of 0.1 g of water at 100°C and normalpressure (1.013 x 105 Nm–2) requires 54 cal of heatenergy to convert to steam at 100°C. If the volumeof the steam produced is 167.1 cc, the change ininternal energy of the sample, is :-
ΔQ = 54 cal = 54 × 4.18 joule = 225.72 joule
ΔW = P[Vsteam – Vwater] [For water 0.1 gram=0.1 cc]
= 1.013 × 105[167.1 × 10–6 – 0.1 × 10–6] joule
= 1.013 × 167 × 10–1 = 16.917 joule
ΔU = ΔQ – ΔW = 225.72 – 16.917
ΔU = 208.8 joule
Two wires are made of the same material and have the same volume. The first wire has cross-sectional area A and the second wire has cross-sectional area 3A. If the length of the first wire is increased by Δl on applying a force F, how much force is needed to stretch the second wire by the same amount ?
The power radiated by a black body is P and it radiates maximum energy at wavelength 0. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength , the power radiated by it becomes nP. The value of n is :-
A set of 'n' equal resistors, of value 'R' each, areconnected in series to a battery of emf 'E' andinternal resistance 'R'. The current drawn is I. Now,the 'n' resistors are connected in parallel to the samebattery. Then the current drawn from batterybecomes 10 I. The value of 'n' is :-
A battery consists of a variable number 'n' of identical cells (having internal resistance 'r' each) which are connected in series. The terminals of the battery are short-circuited and the current I is measured. Which of the graphs shows the correct relationship between I and n ?
A carbon resistor kΩ is to be marked with rings of different colours for its identification. Thecolour code sequence will be :-
Which one of the following statements is incorrect ?
A moving block having mass m, collides withanother stationary block having mass 4m. Thelighter block comes to rest after collision. When theinitial velocity of the lighter block is v, then the valueof coefficient of restitution (e) will be :-
A body initially at rest and sliding along a frictionless track from a height h (as shown in the figure) just completes a vertical circle of diameter AB = D. The height h is equal to :-
Three objects, A : (a solid sphere), B : (a thin circular disk) and C = (a circular ring), each have the same mass M and radius R. They all spin with the same
angular speed ω about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation :-
A tuning fork is used to produce resonance in aglass tube. The length of the air column in this tubecan be adjusted by a variable piston. At room temperature of 27°C two successive resonances are produced at 20 cm and 73 cm column length. If the frequency of the tuning fork is 320 Hz, the velocity of sound in air at 27°C is :-
An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electrical field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in through the same vertical distance h. The time fall of the electron, in comparison to the time fall of the proton is :-
A pendulum is hung from the roof of a sufficiently high building and is moving freely to and fro likea simple harmonic oscillator. The acceleration of the bob of the pendulum is 20 m/s2 at a distanceof 5 m from the mean position. The time period of oscillation is :-
The electrostatic force between the metal plates ofan isolated parallel plate capacitor C having acharge Q and area A, is :-
An electron of mass m with an initial velocity enters an electric field E0 = constant >0) at t = 0. If is its de-Broglie
wavelength initially, then its de-Broglie wavelength at time t is :-
For a radioactive material, half-life is 10 minutes. If initially there are 600 number of nuclei, the time taken (in minutes) for the disintegration of 450 nuclei is:
When the light of frequency 2v0 (where v0 is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is v1. When the frequency of the incident radiation is increased to 5 v0, the maximum velocity of electrons emitted from the same plate is v2. The ratio of v1 to v2 is :-
The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom,is :-
The moment of the force, at (2, 0, –3), about the point (2, –2, –2), is given by:-
A block of mass m is placed on a smooth inclined wedge ABC of inclination θ as shown in the figure. The wedge is given an acceleration 'a' towards the right. The relation between a and θ for the block to remain stationary on the wedge is :-
A toy car with charge q moves on a frictionless horizontal plane surface under the influence of a uniform electric field . Due to the force , its velocity increases from 0 to 6 m/s in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and the average speed of the toy car between 0 to 3 seconds are respectively :-
0 < t < 1s : velocity increases from 0 to 6 m/s
1 < t < 2s : velocity decreases from 6 to 0 m/s
but car continues to move forward
2 < t < 3s : since field strength is same ⇒
same acceleration ∴ car's velocity increases
from 0 to –6 m/s
A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 mm and zero of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of – 0.004 cm, the correct diameter of the ball is :-
Reading of screw gauge
= MSR + VSR × LC + zero error
= 0.5 cm + 25 × 0.001 cm + 0.004 cm
= 0.529 cm
Unpolarised light is incident from air on a plane surface of a material of refractive index 'μ'. At a particular angle of incidence 'i', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation ?
In Young's double slit experiment the separation between the slits is 2 mm, the wavelength of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the fringe angular width to 0.21° (with same andD) the separation between the slits needs to be changed to :-
An astronomical refracting telescope will have large angular magnification and high angular resolution, when it has an objective lens of :-
The volume (V) of a monatomic gas varies with its temperature (T), as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a change from state A to state B, is :-
The fundamental frequency in an open organ pipe is equal to the third harmonic of a closed organ pipe. If the length of the closed organ pipe is 20cm, the length of the open organ pipe is :-
The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is :-
At what temperature will the rms speed of oxygen molecules become just sufficient for escaping from the Earth's atmosphere ?(Given: Mass of oxygen molecule (m) = 2.76 × 10–26 kg Boltzmann's constant kB = 1.38 × 10–23 J K–1) :-
A metallic rod of mass per unit length 0.5 kg m–1 is lying horizontally on a smooth inclined plane which makes an angle of 30° with the horizontal. The rod is not allowed to slide downby flowing a current through it when a magnetic field of induction 0.25T is acting on it in the vertical direction. The current flowing in the rod to keep is stationary is
An inductor 20 mH, a capacitor 100 μF and a resistor 50 Ω are connected in series across a source of emf, V = 10 sin 314 t. The power loss in the circuit is
A thin diamagnetic rod is placed vertically between the poles of an electro-magnet. When the current in the electro-magnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from
When current source is switched on, magnetic field sets up between poles on electromagnet. Diamagnetic material, due to its tendency to move from stronger to weaker field, is thus repelled out.
Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is
If the mass of the Sun were ten times smaller and the universal gravitational constant were ten time larger in magnitude, which of the following is not correct ?
Raindrops will fall faster, Walking on the ground would become more difficult. Time period of a simple pendulum on the earth would decrease.
A solid sphere is in rolling motion. In rolling motion a body possesses translational kinetic energy (Kt) as well as rotational kinetic energy (Kr) simultaneously.The ratio Kt : (Kt + Kr) for the sphere is
The kinetic energies of a planet in an elliptical orbit about the Sun, at positions A, B and C are KA, KB and KC respectively. AC is the major axis and SB is perpendicular to AC at the position of the Sun S as shown in the figure. Then
A solid sphere is rotating freely about its symmetry axis in free space. The radius of the sphere is increased keeping its mass same. Which of the following physical quantities would remain constant for the sphere ?
Which one of the following population interactions is widely used in medical science for the production of antibiotics ?
A mixture of 2.3 g formic acid and 4.5 g oxalic acidis treated with conc. H2SO4. The evolved gaseous mixture is passed through KOH pellets. Weight (ing) of the remaining product at STP will be
Nitration of aniline in strong acidic medium also gives m-nitroaniline because
In acidic medium aniline is protonated to form anilinium ion which is metadirecting.
Which of the following oxides is most acidic in nature?
In metals moving down the group metallic character increases, so basic nature increases hence most acidic will be BeO.
The difference between amylose and amylopectin is
Amylose is long unb ranched chain with α-D-Glucose with held by C1–C4 glucosidic linkage whereas amylopectin is branched chain polymer ofα-D glucose unit in which chain is formed by C1–C4 glycosidic linkage while branching occurs by C1–C6 glucosidic linkage.
Regarding cross-linked or network polymers, which of the following statements is incorrect?
Cross-linked or network polymers are usually formed from bi-functional & tri-functional monomers and contains strong covalent bond between various linear polymer chains like Melamine, Bakelite etc.
Cross-linked or network polymers contain covalent bonds between various polymer chains that may/may not be linear.
In the reaction
the electrophile involved is
Carboxylic acid have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their
Carboxylic acid has higher boiling point than aldehyde, ketone and even alcohols of comparable
molecular mass. This is due to more extensive association through intermolecular H-bonding.
Compound A, C8H10O, is found to react with NaOI (produced by reacting Y with NaOH) and yields a yellow precipitate with characteristic smell. A and Y are respectively
Haloform reaction is shown by compound having
The correct difference between first- and second-order reaction is that
Among CaH2, BeH2, BaH2, the order of ionic character is
BeH2 < CaH2 < BaH2
Smaller the size of cation, more will be its polarising
power. Hence BeH2 will be least ionic.
Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below:
Then the species undergoing disproportionation is:-
Calculate E°cell corresponding to each compound under going disproportionation reaction. The
reaction for which E°cell comes out +ve is spontaneous.
In which case is the number of molecules of water maximum?
Magnesium reacts with an element (X) to form anionic compound. If the ground state electronic configuration of (X) is 1s2 2s2 2p3, the simplest formula for this compound is
Iron exhibits bcc structure at room temperature. Above 900°C, it transforms to fcc structure. The
ratio of density of iron at room temperature to that at 900°C (assuming molar mass and atomic radii of
iron remains constant with temperature) is
Which one is a wrong statement ?
The correct configuration of 'N' is
Consider the following species:
CN+, CN–, NO and CN
Which one of these will have the highest bond order?
Which of the following statements is not true for halogens ?
Due to high electronegativity and small size, F forms only one oxoacid, HOF known as Fluoric (I) acid. Oxidation number of F is +1 in HOF.
Which one of the following elements is unable toform – ion ?
Boron belongs to 2nd period and it does not have vacant d-orbital.
In the structure of ClF3, the number of lone pairs of electrons on central atom 'Cl' is
2 lone pair at equitorial position.
Considering Ellingham diagram, which of the following metals can be used to reduce alumina ?
Mg has more –ΔG value then alumina. So it will be in the lower part of Ellingham diagram. Metals
which has more –ΔG value can reduce those metals oxide which has less –ΔG value.
The correct order of atomic radii in group 13 elements is
In group 13 due to transition contraction [Al > Ga]
The correct order of N-compounds in its decreasing order of oxidation states is
On which of the following properties does coagulating power of an ion depend ?
According to Hardy Schulze rule : The coagulating power of an ion depend on both magnitude and sign of the charge of the ion.
Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations :
pH of which one of them will be equal to 1?
The solubility of BaSO4 in water 2.42 × 10-3 gL–1at 298 K. The value of solubility product (Ksp)will be(Given molar mass of BaSO4 = 233 g mol–1)
Given van der Waals constant for NH3, H2 and CO2 are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied?
Critical temperature vanderwaal constant(a) maximum "a" ⇒ gas with maximum TC ⇒ easiest liquification = NH3
The compound A on treatment with Na gives B, and with PCl5 gives C. B and C react together to give diethyl ether. A, B and C are in the order
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
In substitution reaction alkanes produces alkyl bromides and in Wurtz reaction two alkyl halides are reacted with sodium (Na) metal to form higher alkane.
Since after Wurtz reaction, the gaseous hydrocarbon has less than 4 carbon atoms. So, ′R′ should contain only 1 carbon atom. So D is CH4.
The compound C7H8 undergoes the followin greactions : The product 'C' is
Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity ?
Nitrous oxide (N2O) occurs naturally in environment.
In automobile engine, when fossil is burnt dinitrogen & dioxygen combine to yield NO & NO2.
For the redox reaction
MnO4– + C2O42–+ H+ →Mn2+ + CO2 + H2O
the correct coefficients of the reactants for the balanced equation are
MnO4– C2O4 2– H+
(1) 16 5 2
(2) 2 5 16
(3) 2 16 5
(4) 5 16 2
Which one of the following conditions will favour maximum formation of the product in the reaction,
A2(g) + B2(g) X2(g) ΔrH = –X kJ ?
For reaction ΔH = – ve and Δng = – ve Δ High P, Low T, favour product formation.
The correction factor 'a' to the ideal gas equation corresponds to
Vanderwaal constant (a) forces of attraction.
When initial concentration of the reactant is doubled,the half-life period of a zero order reaction
The bond dissociation energies of X2, Y2 and XY are in the ratio of 1 : 0.5 : 1. ΔH for the formation of XY is –200 kJ mol–1. The bond dissociation energy X2 will be
Identify the major products P, Q and R in the following sequence of reaction :
Which of the following compounds can form azwitterion ?
The molecule which forms zwitter ion is glycine.
The type of isomerism shown by the complex [CoCl2(en)2] is
Which one of the following ions exhibits d–d transition and paramagnetism as well ?
The geometry and magnetic behaviour of thecomplex [Ni(CO)4] are
Iron carbonyl, Fe(CO)5 is
Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code :
Which of the following is correct with respect to –I effect of the substituents? (R= alkyl)
(Based on EN)
∴ –NH2 < –OR < –F –I effect
Also –NR2 < –OR < –F –I effect
Which of the following carbocations is expected to be most stable ?
–NO2 group is meta-directing group
(Less stable due to more e– with drawing effect of–NO2)
(More stable due to less e– with drawing effect of –NO2)
Which of the following molecules represents theorder of hybridisation sp2, sp2, sp, sp from left toright atoms ?
The experimental proof for semiconservative replication of DNA was first shown in a
Select the correct statement :
Offsets are produced by
Which of the following pairs in wrongly matched ?
(1) Starch synthesis in pea : Multiple alleles
(2) ABO blood grouping : Co-dominance
(3) XO type sex determination : Grasshopper
(4) T.. morgan : Linkage
Which of the following flowers only once in its life-time?
Select the correct match :
Which of the following has proved helpful inpreserving pollen as fossils?
Stomatal movement is not affected by
The stage during which separation of the paired homologous chromo somes begins is
The two functional groups characteristic of sugars are
There are two types of sugar: Aldose and Ketose, both of which contain the carbonyl group and without it it won’t be considered sugar.
If we consider the anomer's glucose the position of the hydroxyl group decides the type of glucose, making it a very important characteristic group of sugar.
Hence D is correct.
Which of the following is not a product of light reaction of photosynthesis ?
Stomata in grass leaf are
Which among the following is not a prokaryote ?
Which of the following is true for nucleolus ?
The Golgi complex participates in
Golgi complex is the double membrane-bounded organelle present in eukaryotic cells only. It takes part in the formation of secretory vesicles. It helps in transportation of material within or outside the cells. Whereas respiration in bacteria is done by mesosomes, activation of an amino acid is the part of protein synthesis occurs in ribosomes and breakdown of fatty acid by beta-oxidation occurs in mitochondria.
In stratosphere, which of the following element actsas a catalyst in degradation of ozone a release ofmolecular oxygen ?
Which of the following is a secondary pollutant
Natality refers to
What type of ecological pyramid would obtained with the following data ?
Secondary consumer : 120 g
Primary consumer : 60 g
Primary producer : 10 g
World Ozone Day is celebrated on
Which of the following is commonly used as a vectorfor introducing a DNA fragment in human lymphocytes ?
In India, the organisation responsible for assessingthe safety of introducing genetically modified organisms for public use is
A 'new variety of rice was patented by a foreign company though such varieties have been presentin India for a long time. This is related to
Select the correct Match :
Use of bio-resources by multinational companies and organisations without authorisation from the concerned country and its peoople is called
The correct order of steps in Polymerase Chain Reaction (PCR) is
Secondary xylem and phloem in dicot stem are produced by
Pneumatophores occur in
Sweet potato is a modified
Which of the following statement is correct ?
Select the wrong statement :
Casparian strips occur in
Plants having little or no secondary growth are
Which one is wrongly matched ?
Match the items given in Column I with those in Column II and select the correct option given below :-
Winged pollen grains are present in
After karyogamy followed by meiosis, spores are produced exogenously in
Agaricus belogs to basidiomycetes where basidiospores are produced exogenously after karyogamy ,in neurospora sexual spores are produced endogenously.
What is the role of NAD+ in cellular respiration ?
Oxygen is not produced during photosynthesis by
Pollen grains can be stored for several years in liquid nitrogen having a temperature of
In which of the following forms is iron absorbedby plants ?
Double fertilization is
Which of the following elements is responsible formaintaining turgor in cells ?
Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?
Hormones secreted by the placenta to maintain pregnancy are
The contraceptive 'SAHELI'
The difference between spermiogenesis and spermiation is
The amnion of mammalian embryo is derived from
In a growing population of a country
All of the following are included in 'Ex-situ conservation' except
Sacred groves included in in-situ conservation.
Which part of poppy plant is used to obtain thedrug. "Smack" ?
Match the items given in Column I with those in Column II and select the correct option given below:
Match the items given in Column I with those Column II and select the correct option given below:
The similarity of bone structure in the fore limbs of many vertebrates is an example of
Which of the following is not at autoimmune disease?
Among the following sets of examples for divergent evolution, select the incorrect option :
Which of the following characteristics represent Inheritance of blood groups' in humans?
c. Multiple dominance
d. Incomplete dominance
e. Polygenic inheritance
ABO blood grouping is an example of multiple alleles iA and iB show Dominance AB shows co dominance.
In which disease does mosquito transmitted pathogen cause chronic inflammation of lymphatic vessels?
Conversion of milk to curd improves its nutritional value by increasing the amount of
Which of the following is an amino acid derived hormone ?
Which of the following structures or regions is incorrectly paired with its function ?
Which of the following hormones can play a significant role in osteoporesis ?
The transparent lens in the human eye is held inits place by
Which of the following animals does not undergo metamorphosis?
Identify the vertebrate group of animals characterized by crop and gizzard in its digestive sytstem.
Crop and and gizzard mostly found in digestive tract of aves.
Which of the following organisms are known as chief producers in the oceans ?
Which one of these animals is not a homeotherm?
Ciliates differ from all other protozoans in
Which of the following features is used to identifya male cockroach from a female cockroach ?
Which of the following options correctly representsthe lung conditions in asthma and emphysema,respectively ?
Match the items given in Column I with those in Column II and select the correct option given below:
Match the items given Column I with those in Column II and select the correct option given below :
AGGTATCGCAT is a sequence from the codingstrand of a gene. What will be the corresponding sequence of the transcribed mRNA ?
According to Hugo de Vries, the mechanism of evolution is :-