A to Z Exams

A flint glass prism is of refracting angle 50.Its refractive index for C line is 1.790 and for F line is 1.805.The angular dispersion of C and F lines is

An electron remains undeflected when passing perpendicular to mutually perpendicular electric and magnetic fields. If the magnetic field is 8 Gauss and the electric field is 400 V/m, the velocity of the electron is:

An open pipe resonates to a frequency ‘f1’ and a closed pipe resonates to a frequency ‘f2’.If they are joined together to form a longer tube,then it will resonate to a frequency of(neglect end corrections)

A motor cycle starts from rest and accelerates along a straight path at 2m/s2.At the starting point of the motor cycle, there is a stationary electric siren. How far has the motor cycle gone when the driver hears the frequency of the siren at 94% of its value when the motor cycle was at rest?(speed of sound=330ms-1)

In an electric motor,wires carrying a current of 5A are placed at right angles to magnetic field of induction 0.8T.If each wire has length of 20cm,then the force acting on each wire

The elementary particles heavier than nucleons are called

For the system S(s)+O2(g)→SO2(g)?

The phase difference between two vibrating particles separated by a distance of 11 metres into medium through which a progressive wave is travelling is 13200.If the frequency of the disturbance is 105 Hz, the phase velocity of the progressive wave in ms-l

The frequency of a stretched uniform wire under tension is in resonance with the fundamental frequency of a closed tube. If the tension in the wire is increased by 8 N, it is in resonance with the first over- tone of the closed tube. The initial tension in the wire is

When a positively charged particle enters a uniform magnetic field with uniform velocity, its trajectory can be : 1) a straight line 2) a circle 3) a helix

A parallel plate capacitor has a capacity 80x10-6 when air is present between the plates.The volume between the plates is then completely filled with a dielectric slab of dielectric constant 20. The capacitor is now connected to a battery of 30 V by wires. The dielelctric slab is then removed. Then, the charge that passes now through the wire is

Frequency of tuning fork A is 250 Hz. It produces 4 beats/sec with another tuning fork B. When A is filed, the beat frequency is 6 beats/sec. The frequency of B is

Two vibrating tuning forks produce vibrations at the tympanic of an observer represented by y1=4sin(260 πt) and y2=4sin(256 πt).The number of beats heard by the observer in one minute is

There is no couple acting when two bar magnets are placed coaxially separated by a distance because:

A potentiometer wire of length 100 cm has a resistance of 10 Ω. It is connected in series with a resistance and a cell of emf 2V and of negligible internal resistance. A source of emf 10 mV is balanced against a length of 40 cm of the potentiometer wire. The value of external resistance is:

A steel wire can withstand a load up to 2940 N, A load of 150 kg, is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position, so that the wire does not break when the load passes through the position of equilibrium, is

Electrons ejected from the surface of a metal, when light of certain frequency is incident on it, are stopped fully by a retarding potential of 3 volts. Photoelectric effect in this metallic surface begins at a frequency 6 x 1014s-1. The frequency of the incident light in s-1is : [ Planck's constant = 6.4 x 10-34Js, charge on the electron = 1.6 x 10-19C]

Consider the following statements A and B and identify the correct answer :(A) : In an elastic collision, if a body suffers a head on collision with another of same mass atrest, the first body comes to rest while the other starts moving with the velocity of the first one.(B) : Two bodies of equal mass suffering a head on elastic collision merely exchanges their velcities :

A train is travelling at 120 Kmph and blows a whistle of frequency 1000Hz.The frequency of the note heard by a stationary observer if the train is approaching him and moving away from him are (Velocity of sound in air =330 ms-1)nearly

In a parallel plate air capacitor of capacitance 4 farad, if the lower half of air space is filled with a material of dielectric constant 3 its capacitance changes to

A prism of refractive index μ and angle A is placed in the minimum deviation position. If the angle of minimum deviation Is A, then the value of A in terms of μ is

Two charges of 50μC and 100μC are separated by a distance of 0.6m.The intensity of electric field at a point midway between them is

Three condensers 1μF,2μF and 3μF are connected in series to a p.d of 330volt.The PD across the plates of 3μF is

In Millikans oil drop experiment, an oil drop of radius r charge q falls under the gravity with a terminal velocity Vg and moves up with a terminal velocity Ve in the uniform vertical electric field of intensity E. If η is coefficient of viscosity of air, the charge of oil drop is

A body of mass m1 moving with a velocity 10 ms-1 collides with another body at rest of mass m2 After collision the velocities of the two bodies are 2 ms-1 and 5 ms-1respectively, along the direction of motion of m1.The ratio m1/ m2

A long rigidly supported wire carries a current ia=96A.Directly above it and parallel to it at a distance,another wire of 0.144N weight per metre carrying a current ib=24A,in a direction opposite to that air due to magnetic repulsion,then its distance(in mm) from the lower wire is

A free neutron decays spontaneously into :

In order to double the frequency of the fundamental note emitted by a stretched string, the length is reduced to 3/4th of the original length and the tension is changed. The factor by which the tension is to be changed is:

A stretched string of length 2m is found to vibrate in resonance with a tuning fork of frequency 420Hz.The next higher frequency for which resonance occurs is 490Hz.The velocity of the transverse wave along this string is

One junction of thermo couple is at 00C and the other junction is heated .Maximum current in the thermo couple is observed when hot junction is at 2400C.The temperature of the hot junction at which the direction of current reverses is

A source of sound is approaching a stationary observer with a velocity 1/10th of the velocity of sound in air so that apparent decrease in the wavelength of sound waves is 10cm.If the observer is approaching the same source of sound at rest with a velocity 1/5th of velocity of sound in air,the apparent increase in the frequency of sound is(velocity of sound in air=340m/s)

Two identical piano wires have a fundamental frequency of 600 c/s when kept under the same tension. What fractional increase in the tension of one wire will lead to the occurrence of 6 beats per second when both wires vibrate simultaneously      

The frequency of the sound of a car horn as recorded by an observer towards whom the car is moving differs from the horn by 10%. Assuming the velocity of sound in air to be 330ms-1, the velocity of the car is

The direction of the magnetic field produced by straight current carrying conductor is given by

Two cylinders 'A' and 'B' fitted with pistons contain equal number of moles of an ideal mono-atomic gas at 400 K. The piston of 'A' is free to move while that of 'B' is hold fixed. Same amount of heat energy is given to the gas in each cylinder. If the rise in temperature of the gas in 'A' is 42 K, the rise in temperature of the gas in 'B' is

The work function of a certain metal is 3.31 x 10-19 J. Then the maximum kinetic energy of photo electrons emitted by incident radiation of wavelength 5000 A0 is

An infinitely long thin straight wire has uniform linear charge density of 1/3 coul.m-1.Then the magnitude of the electric intensity at a point 18 cm away is

A train approaching a level crossing at a speed of 20m/s sounds a horn of frequency 628Hz when 80m form the crossing.A person is standing at 60m from the level crossing on a road which is perpendicular to the railway track.Then the apparent frequency heard by the person is (velocity of sound in air is 330m/s)

A man 50 kg is standing at one end on a boat of length 25 m and mass 200 kg. If he starts running and when he reaches the other end, he has a velocity 2 ms-1 with respect to the boat.The final velocity of the boat is : (in ms-1)

Indium impurity in germanium makes it into a

A quantity of heat Q is supplied to a mono atomic ideal gas which expands at constant pressure. The fraction of heat that goes into work done by the gas is :

The frequency of transverse vibrations in a stretched string is 200 Hz.If the tension is increased 4 times and the length is reduced to one fourth the original values,the frequency of vibrations will be

A sphere of radius 1m encloses a charge of 5μC. Another charge of -5μC is placed inside the sphere. The net electric flux would be

The waves are prepared by the following equations y1=5 sin2π(10t-0.1x) y2=10sin2 π(20t-0.2x) ratio of intensities I2/I1 will be

Along straight conductor carrying a current of 2A is in parallel to another conductor of length 5 cm and carrying a current 3A. They are separated by a distance of 10cm B due to first conductor at second conductor is

A man stands infront of a hill rock and fires a gun. He hears an echo after 1.5 sec. the distance of the hill rock form the man is (velocity of sound in air = 330m/s)

A source and an observer move away from each other, each with a velocity of 10 m/s. with respect to ground If the observer find the frequency of sound coming from tile source as 1950 Hz, the original frequency of the source is: (assume velocity of sound in air = 340 m/s)

In a series LCR a.c circuit R=50Ω and the impedance Z=100Ω. Then the phase difference between the current and applied voltage is (in radius)

The rear side of truck is open and box of mass 50kg is placed at 3.2m away from the open end.The coefficient of friction between the box and the surface is 0.2. if the truck starts from rest and moves on a straight road with acceleration 2.1ms-2 the box falls off the truck after a time (g=10ms-2)

The mass of a balloon with its contents is 15kg. It is descending with an acceleration equal to half that of acceleration due to gravity. If it is to go up with the same acceleration, keeping the volume same, its mass should be decreased by

A man stands in front of a hillock and fires a gun. He hears an echo after 1.5s.The distance of the hillock from the man is (velocity of sound in air is 330 m/s)

Two identical stringed instruments have a frequency of 100Hz.The tension in one of them is increased by 4%.If they are now sounded together the number of beats per second is

The loss of weight of a solid when immersed in a liquid at 00C is .If α and β are the volume coefficients of the solid and the respectively, then the loss of weight at C is approximately

To measure the field B between the poles of an electromagnet,a small test loop of area 1cm2,resistance 10Ω and 20 turns is pulled out of it.A galvanometer shows that the total charge of 2μC passed through the loop.The value of resistance connected in series is

An ideal gas at a pressure of 1 atm and temperature of 270C is compressed adiabatically until its pressure becomes 8 times the initial pressure, then final temperature is : (γ = 3/2)

A car moving with a speed of 72kmph towards a hill.Car blows horn at a distance of 1800m from the hill.If echo is heard after 10s,the speed of sound (in ms-1) is

Work done by 0.1 mole of gas at 270C when it expands to double its volume at constant pressure is : (assume R = 2 cal/mol-1 K-1)

An iron sphere of mass 20 x 10-3 kg falls through a viscous liquid with terminal velocity 0.5 ms-1. The terminal velocity (in ms-1) of another iron sphere of mass 54 X 10-2 kg is :

A tuning fork A of frequency 384Hz produces 3 beats/second when sounded with a second tuning fork B of unknown frequency.When a is filed a little,the number of beats decreased to 2 beats/second.The frequency of the fork B must be

The area of the coil in a moving coil galvanometer is 15cm2 and has 20 turns.The magnetic inductions is 0.2T and the couple per unit twist of the suspended wire is 10-6 Nm per degree.If the deflection is 450,the current passing through it is

Two cells A and B are connected in the secondary circuit of a potentiometer one at a time and the balancing length are respectively 400 cm and 440 cm. The emf of the cell A is 1.08 volt. The emf of the second cell B in volts is :

Two solid spheres (A and B) are made of metals of different densities and ρA  and ρB  respectively. If their masses are equal, the ratio of their moments of inertia {IB/IA) about their respective diameter is

A car of mass 400 kg and travelling  at 72 kmph crashes into a truck of mass 4000 kg and travelling at 9 kmph, in the same direction. The car/bounces back at a speed of 18 kmph.The speed of truck after the impact is

A body is projected from the earth at angle 300 with the horizontal with some intial velocity. If its range is 20 m, the maximum height reached by it is : (in metres)

When two capacitors are joined in series the resultant capacity is 2.4 μF and when the same two are joined in parallel the resultant capacity is 10μF.their individual capacities are

A constant voltage of 25 V is applied to a series L-R circuit at t = 0, by closing a switch. What is the potential difference across the resistor and the inductor at time t = 0

A magnetic needle lying parallel to a magnetic field is turned through 600.The work does on it is w. The torque required to maintain the magnetic needle in the position mentioned above is

A black body radiates energy at the rate of E watt/m2 at a high temperature T K. When the temperature is reduced to (T/2) K, the radiant energy is

An intrinsic semi conductor has 1018/m3 free electron and is doped with pentavalent impurity of 1024/m3.Then the free electrons density order increases by

A 6 V cell with 0.5 Ω  internal resistance, a 10 V cell with 1 Ω internal resistance and a 12 Ω external resistance are connected in parallel. The current (in ampere) through the 10 V cell is :

The lengths of two wires made of same material are 2m and 1m. Their radii are 1mm and 2mm. The ratio of their specific resistances is

The ratio of effective focal length of Huygens eye piece and the object distance of its field lens is

A wire of length l having tension T and radius r vibrates with fundamental frequency f.Another wire of the same metal with length 2l having tension 2T and radius 2r will vibrate with fundamental frequency

When a wave travels in a medium the particles displacement is given by the equation y(x,t) = 0.03 sin π(2t - 0.01 x) where y and x are in metres and t in seconds. The wavelength of the wave is :

Emission of electrons in photoelectric effect is possible if :

A clock pendulum made of invar has a period of 0.5 s , at 200 C . If the clock is used in a climate where the temperature averages to 300 C how much time does the clock loose in each oscillation (for invar α = 9 x 10-70 C and g = constant

A proton is projected with a velocity 107ms-1 ,at right angles to a uniform magnetic field of induction 100mT.The time(in seconds)taken by the proton to traverse 900 arc is:(Mass of proton=1.65x10-27kg and charge of proton = 1.6x10-19C

A ball is thrown vertically upwards with a speed of 10m/sec from the top of a tower 200m high and another is thrown vertically downwards with the same speed simultaneously. The time difference between them in reaching the ground, in seconds, if g is taken as 10 m/s2, is:

Two wires A and B are of lengths 40 cm and 30 cm, A is bent into a circle of radius r and B into an arc of radius r. A current i1 passed.through A and i2 through B. To have the same magnetic inductions at the centre, the ratio of    i1  :   i2  is

Two lenses of focal lengths +10cm, and -15cm when put in contact behave like a convex lens .They will have zero longitudinal chromatic aberration if their dispersive powers are in the ratio

A thin metal disc of radius 0.25 m and mass 2 kg starts from rest and rolls down an Inclined plane. If its rotational kinetic energy is 4 J at the foot of the inclined plane, then its linear velocity at the same point is:

To a charged particle which is moving with a constant initial velocity v, uniform magnetic field is applied in the direction ot the velocity :

A bar magnet of 10 cm long is kept with its north (N)-pole pointing North. A neutral point is formed at a distance of 15 cm from each pole. Given the horizontal component of earth's field is 0.4 Gauss, the pole strength of the magnet is

A potentiometer having wire of 4m length is connected to the terminals of a battery with a steady voltage.A leclanche cell has a null points at 1m,If the length of the potentiometer wire is increased by 1m,the position of the null points is

The area of the coil in moving coil galvanometer is 80 cm2 and its has 200 turns. The magnetic induction of the radial field is 0.2T and the couple per unit twist of the suspension wire is 2 x 10-6Nm per degree. If the deflection is 40,the current passing through it is

A tuning fork A of frequency 384Hz produces 3 beats/second when sounded with a second tuning fork B of unknown frequency.When A is filed a little,the number of beats decreased to 2beats/second.The frequency of the fork B must be

A fire engine with its bell ringing with a frequency of 200 Hz is moving with a velocity of 54 kmph towards an observer at rest near a hut on fire. The apparent frequency of sound heard by the observer is (velocity of sound in air = 300ms-1)

Match the appropriate pairs from Lists I and II: List-I List-II 1.NItrogen molecules A.continuous spectrum 2.Incandescent solids B.Absorption spectrum 3.Fraunhoffer lines C.Band spectrum 4.Electric arc between iron rods D.Emission spectrum

A 20F capacitor is charged to 5V and isolated. It is then connected in parallel with an uncharged 30F. The decrease in the energy of the system will be

A transverse wave propagating on a stretched string of linear density 3x10-4kgm-1 is represented by the equation y=0.2sin(1.5x+60t) where x is in meter and t is in seconds. The tension in the string in N.

A long string with a charge of λ per unit length passes through an imaginary cube of edge a. The maximum flux of the electric field through the cube will be

Thermo emf produce per 10C temperature difference between the junction is 0.005V.when cold junction is at 100C,and hot junction is at t0C,thermo emf produced is 0.5 V.,The value of t is

An infinite number of charges each of magnitude q are placed on x-axis at distances of 1, 2, 4, 8, ….. meter from the origin. The intensity of the electric field at origin is

The relation between the coefficient of real expansion (γr) and coefficient of apparent expansion (γa) of a liquid and the coefficient of linear expansion (αg) of the material of the container is

The work function of the nickel is 5 eV. When a light of wavelength 2000 Ao falls on it, it emits photo electrons in the circuit. Then the potential difference necessary to stop the fastest electrons emitted is (given h = 6.67 x  10-34 J-s)

(A): bending of a conducting wire effects electrical resistance (R): Resistance of a wire depends on resistivity of that material

A 2 MeV proton is moving perpendicular to a uniform magnetic field of 2.5 tesla. The force on the proton is (mass of proton = 1.6 x 10-27 kg)

An object of mass 2 m is projected with a speed of 100 ms-1    at an angle θ = sin-1 (3/5) to the horizontal. At the highest point, the object breaks into two pieces of same mass m and the first one comes to rest. The distance between the point of projection and the point of landing of the bigger piece (in meter) is (Given g =10 m/s2)    

A car is moving with a speed of 72 km/h towards a hill. Car blows horn at a distance of 1800 m from the hill. If echo is heard after 10 seconds, the speed of sound (in m/sec.) is

A radioactive sample has half life of 5 days. To decay from 8 micro-curies to 1 micro-curie, the number of days taken will be :