The phase angle between e.m.f. and current in LCR series A.C. circuit is
The threshold frequency for photo electric effect for a metal surface is found to be 4.8 x 1016 Hz . The stopping potential required when the metal is irradiated by radiation of frequency 5.6 x 1016 Hz is taking h = 6.6 x 10−34 J sec and e = 1.6 x 10−19 C
The e.m.f. of a cell is E volts and internal resistance is r ohm. The resistance in external circuit is also r ohm. The p.d. across the cell will be
Three different capacitors are connected in series. Then:
A block of mass m at the end of a string is whirled round in a vertical circle of radius R. The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top is
The effective value of a.c. in a circuit is 10 A. The peak value of current is
In a transformer, the number of turns of primary coil and secondary coil are 5 and 4 respectively. If 240 V is applied on the primary coil, then the ratio of current in primary and secondary coil is
Which of the following waves have maximum wavelength?
Two wires of the same metal have same length, but their cross-sectional areas are in the ratio 3 : 1. If resistance of the thicker wire is 10 Ω, then total resistance of the wires in series combination will be
The electric potential V is given as a function of distance x (metre) by V = (5x2 + 10x - 9) volt. Value of electric field at x = 1m is
V = 5x2 + 10x - 9
E = - dv/dx
= - (10x + 10)
= -(10 x 1 + 10)
= - 20 V/m
When a body is connected to the earth, then electron from the earth, flow into the body. It means that the body is
A box is placed on an inclined plane and has to be pushed down. The angle of inclination is
The time-period of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun?
As we go from the equator to the poles, the value of g
At a common temperture, a block of wood and a block of metal feel equally cold or hot. The temperatures of block of wood and block of metal are
In Young's double slit experiment, the fringe width is β. If the entire arrangement is placed in a liquid of refractive index μ, the fringe width becomes
At which temperature the velocity of O₂ molecules will be equal to the velocity of N₂ molecules at 0ºC
A long copper pipe carries a current. Then the magnetic field is
Cathode rays and canal rays produced in a certain discharge tube are deflected in the same direction, if
In discharge tube cathode rays (a beam of negative particles ) and canal rays (positive rays) moves opposite to each other.
They will experience a magnetic force in the same direction, if a normal magnetic field is switched on.
The magnetic moment of a circular coil carrying current is
The ratio of magnetic moments of two short magnets which give deflection in tan B position when placed at 12cm and 18cm from centre of a deflection magnetometer is
According to question:
Rate of change of torque τ with deflection θ is maximum for a magnet suspended freely in a uniform magnetic field of induction B, when
A tangent galvanometer is used to measure
An air bubble of radius 10 mm is rising at a steady rate of 8 mm-s⁻1 through a liquid of density 1.47x103 kg-m⁻3. Neglecting density of air, the coefficient of viscosity of the liquid is (Take g = 9.8 m-s2)
The moment of inertia of a sphere of radius R and mass M about a tangent to the sphere is
The breaking stress of a wire depends upon
A body floats in a liquid contained in a beaker. If the whole system falls under gravity, then the upthrust on the body due to liquid is
A body released from a great height falls freely towards earth. Another body is released from the same height exactly one second later. The separation between the two bodies two seconds after the release of the second body is
A ball of mass 100g is moving with a velocity of 10m/sec and hits a bat and rebounds with a velocity of 10 m/s. The force of the blow by the bat acts for 0.01 sec. The average force exerted on the ball by the bat is
The nucleus of 56Ba141 contains ---- neutrons
A simple harmonic oscillator has a period T and energy E. The amplitude of the oscillator is doubled. Choose the correct answer.
In a camera, the time of exposure for good quality prints depends upon
Which of the following cannot be emitted by radioactive substances during their decay?
When green light is incident on a certain metal surface electrons are emitted, but no electrons are emitted by yellow light. If red light is incident on the same metal surface then
Work function of a metal is 2.1 eV. Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface
A body of mass 0.5 kg is projected under gravity with a speed of 98 m/s at an angle of 30º with the horizontal. The change in momentum (in magnitude) of the body is
If the refrective index of a material of equilateral prism is √3, then angle of minimum deviation of the prism is
A beam of light composed of red and green rays is incident obliquely at a point on the face of a rectangular glass slab. When coming out on the opposite parallel face, the red and green rays emerge from
In Foucaults rotating mirror experiment to determine the velocity of light in air, the distance of the rotating mirror from the concave mirror is 6000 metres. The reflected ray is displaced through an angle of 48π x 10−2 radians. If the velocity of light in air is 3 x 104 ms−1 , the number of rotations made by the rotating mirror in one minute are
A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. If ' μ ' is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse is
A rigid body is rotating about an axis. To stop the rotation, we have to apply
A spring has a certain mass suspended from it and its period for vertical oscillation is T. The spring is now cut into two equal halves and the same mass is suspended from one of the halves. The period of vertical oscillation is now
The period of spring oscillating simple harmonically
To a germanium sample, traces of gallium are added as an impurity. The resultant sample would behave like a/an
If the forward voltage in a semiconductor diode is doubled, the width of the depletion layer will
Two sound waves of wavelengths 5 m and 6 m formed 30 beats in 3 seconds. The velocity of sound is
A capillary tube made of glass is dipped into mercury. Then
The amount of heat produced in a conductor, due to the flow of current, is directly proportional to
A 220 volt and 800 watt electric kettle and three 220 volt and 100 watt bulbs are connected in parallel. On connecting this combination with 220 volt electric supply, the total current will be
Three equal resistors connected in series across a source of e.m.f. together dissipate 10 watt. If the same resistors are connected in parallel across the same e.m.f., then the power dissipated will be
A glass flask of volume 200 cm3 is completely filled with mercury at 20º C . The amount of mercury that spilt over when the flask is heated to 80º C is (coefficient of volume expansion of glass is 27 x 10−6 ∕ ºC , mercury is 0.18 x 10 − 3 ∕ ºC )
The amount of heat required to raise the temperature of a body through 1 K is called, its
An ice cream has a marked value of 700 cal. How many kilowatt-hour of energy will it deliver to the body as it is digested?
1 kcal = 103 Calorie = 4200J
Identity the pair whose dimensions are equal
Unit of self inductance is
A train is approaching a platform with a velocity ν. The frequency heard by an observer standing at the station is
The superposition principle applies to
The length of a sonometer wire tuned to a frequency of 250 Hz is 0.60 metre. The frequency of tuning fork with which the vibrating wire will be in tune when the length is made 0.40 metre is
Reverberation time does not depend upon
If a body looses half of its velocity of penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest
What are X and Y in the reaction
Which of the following does not give iodoform test ?
Acetylene reacts with ammonical silver nitrate to form
The metal ion which is precipitated when H₂S is passed with HCl is
The four quantum numbers of the valence electron of potassium are
Splitting of spectral lines under the influence of magnetic field is called
The atomic number of an element 'M' is 26. How many electrons are present in the M-shell of the element in its 'M' state?
Which of the following alkyl group has the maximum + I effect?
The percentage of s-character in the hybrid orbitals sp, sp2 and sp3 follows the pattern
In [AgCN2]− , the number of π bonds is
If a reaction involves only solids and liquids,Which of the following is true ?
According to Le-Chatelier's principle, adding heat to a solid and liquid in equilibrium will cause the
If the rate of a reaction is equal to the rate constant, them the order of reaction of
If an endothermic reaction is non-spontaneous at freezing point of water and becomes feasible at its boiling point, then
Which of the following statements is true?
The drug given during hypertension is
The homologue of ethyne is
The correct order of electron affinity among the following is
The electron affinity of fluorine is unexpectedly less than that of Cl. Because the size of F atom is quite small, as a result, the electron-electron repulsions in the relatively compact 2p-subshell are comparitively large and hence, the incoming electron is not accepted with the same ease as in the case with Cl.
For a cell, the cell reaction is
Mg (s) + Cu2 + (aq) → C u(s) + Mg2 + (aq)
If the standard reduction potentials of Mg and Cu are -2.37 and +0.34 V respectively, the EMF of the cell is
The IUPAC name of K₃ [Ir (C₂O₄)₃] is
The chief source of iodine, in which it is present as sodium iodate, is
The temperature at which the second virial coefficient of a real gas is zero is called
Volume of 4.4 of CO₂ at N.T.P. is
Among alkali metal salts, the lithium salts are the poorest conductors of electricity in aqueous solution because of
Bauxite is an ore of
The shape of gaseous SnCl₂ is
Which of the following is most dense?
Which type of bond is there in H₂S molecules ?
The comparatively high b.p. of HF is due to
Which of the following carbonates decomposes on heating?
The number of oxygen atoms bonded to one phosphorus atom in P4O6 is
Decomposition of H₂O₂ is favoured by
Neutralization of an acid with a base, invariably results in the production of
At infinite dilution, the percentage ionisation for both strong and weak electrolytes is
Benzoic acid gives benzene on being heated with X and phenol gives benzene on being heated with Y. Therefore X and Y are respectively
Ca2⁺ is isoelectronic with
Why only As⁺3 gets precipitated as As₂S₃ and not Zn⁺2 as ZnS when H₂S is passed through an acidic solution containing As⁺3 and Zn⁺2?
R and S pairs of enantiomers differ from one another in
Radioactivity is due to
Which of the following will not give the iodoform test?
Which of the following compounds will be optically active?
Which of the following is the example of SN2 reaction?
following step is:
CH3CH3 + Cl. → CH3CH2 + HCl
The order of decreasing ease of reaction with ammonia is
Ethylbenzene with bromine in presence of FeBr₃ predominantly gives
Atomic numbers of Cr and Fe are respectively 24 and 26. Which of the following is paramagnetic?
Which of the following is the most powerful oxidising agent ?
Phenol is heated with phthalic anhydride in presence of conc. H₂SO₄. The product gives pink colour with alkali. The product is
The process involving heating of rubber with sulphur is called
In which of the following complexes, oxidation state of metal is zero ?
Molecular mass of a volatile substance may be obtained by
Van't Hoff factor of Ca(NO₃)₂ is
When a strong beam of light is passed through a colloidal solution, the light is
Which of the following represents ferrimagnetism?
Of the following compounds, which will have zero dipole moment?
The freezing point of 1 molal NaCl solution assuming NaCl to be 100% dissociated in water is
ΔTf = i x Kf x m = 2 x 1.86 x 1 = 3.72º
The percentage of P₂O₅ in diammonium phosphate (NH₄)₂ HPO₄ is
The valence shell of transition elements consist of
Which one of the following has the least magnetic moment ?
The atrioventricular (AV) node stimulates the
Mitosis is absent in
Anetennae of male mosquito is
An association mutually beneficial to both partners is represented by:
The processes of chewing are referred to as _____.
Damaged or old red blood cells are removed by the liver and _____.
Which one is a source of rubber?
Which of the following is grown as the most important source of textile fibres in Bengal?
In jaundice level of which one of the following increases in blood.
Which mineral is essential for coagulation to occur?
In India hocky sticks are generally made from
Cast nets are used to catch
The scientist who coined the term ecosystem was
Which of the following represents an organism and its ecological niche?
Each species of a community lives in a very specific part of a habitat and perform certain functions. The habitat together with the functions of a species is called ecological niche of the species. Plant lice (aphids) which suck plant sap from the leaves represent the ecological niche of the species
Lead arsenate is a
Daily rhythms are associated with
Which of the following is an inherited disorder ?
In Gymnosperms the only mode of pollination is -
Most of the contraceptive pills contain
Plains with snow, ice, and frozen soil for most of the year are found in
In a mutational event, when adenine is replaced by guanine, it is a case of
1:1 ratio of test cross indicates that
Tay-Sachs disease is associated with
A heterozygous indivdual is crossed with a homozygous dominant parent, it is a
In a male human being, sperms contain autosomes and
In humans, the female is homozygous and male is heterozygous for the sex chromosomes.
The nuclei of human cells contain 22 autosomes and 2 sex chromosomes. In females, the sex chromosomes are the 2 X chromosomes and Males have both one X chromosome and one Y chromosome.
During maturation, the sex chromosomes segregate freely like autosomes, so that ovum receives a x-chromosome and sperm receives a either x or y chromosome.
Sensation of stomach pain is due to
Where the optic nerve leaves the eye, the retina has no rods and cones and the images falling in this area cannot be perceived. This area is referred to as the
Minerals absorbed by roots move to the leaf through
Filter feeding occurs in
The cells within the thymus gland probably originated from the _____.
Cold blooded animal is the one which has
Which of the following is TRUE of lymph nodes?
Cavity lodging lungs is
Bacterial photosynthesis contains
Six kingdom classification was suggested by
Conversion of ATP to ADP produces
Renewable source of energy is
Some early experiments on phototropic curvature in grasses led to discovery of
Growing plants in dark that causes bending
In a sponge, digestion takes place in
In which one of the following pathogens do the cells of promycelium after the germination of teleutospore produce infection hyphae instead of basidiospores?
Rubber is obtained from
Nitrogen fixation occurs in
Pollutant emitted by paddy fields is
Chlorofluorocarbons are not being used in refrigerators because they
Clitoris in mammals is
NADH of glycolysis reacts with an inorganic element during liberation of energy. The respiration is
Alchol is a product of
A cob of maize has long tassels of hairs which are
Haemoglobin releases oxygen at the tissues if
Meiosis can be best observed in the
Mucus is moved along the respiratory tract by
A frog has
Which of the following family plants having tricarpellary, syncarpous unicellular gynoecium with inferior ovary -
Stem is specialised to perennate and store food in
When water enters the plant cell, then pressure exerted on the cell wall is called
Which is not correct for Earthworm?
Which of the following describes the tissues surrounding the loop of Henle?