A to Z Exams

The locus of the centre of a circle which cuts the circles 2x2+2y2-x-7=0 and 4x2+4y2-3x-y=0 orthogonally is a straight line whose slope is

A condenser of capacity 10 μF is charged to a potential of 500 V. Its terminals are then connected to those of an uncharged condenser of capacity 40 μF. The loss of energy in connecting them together is

The third overtone produced by a vibrating string 2m long is 1200 Hz. The velocity of propagation of the wave is

The ratio of specific heats of a gas is γ.The change in internal energy of one mole of the gas, when the volume changes from V to 2V at constant pressure P is

A transformer steps up an A.C. voltage from 230V to 2300V. If the number of turns in the secondary coil is 1000, the number of turns in the primary coil will be

The Poisson's ratio of a material is 0.4. If a force is applied to a wire of this material, there is a decrease of cross-sectional area by 2%. The percentage increase in its length is:

A sonometer consists of two wires of same material whose radii are in the ratio2:3.The tension in thick wire is 4 times the tension in thin wire.If V is velocity of transverse were in thin wire,then the velocity of transverse wave in thick wire is

An electron beam moving with a speed of 2x107ms-1 enters a magnetic field of induction 3x10-3T, directed perpendicular to its direction of motion. The intensity of electric field applied so that the electron beam is undeflected due to the magnetic field is

A train is approaching with a uniform velocity of 72kmph and the frequency of the whistle of that train is 480 Hz.The apparent increase in the frequency of that whistle heard by a stationary observer on the platform is(Velocity of sound in air is 340ms-1)

An explosion of atomic bomb releases an energy of 7.6x1013J.If 200 MeV energy is released on fission of one 235U atom the number of uranium atoms undergoing fission,and the mass of uranium used in the bomb is

In Ramsden eyepiece, the two planoconvex lenses each of focal length / are separated by a distance 12 cm. The equivalent focal length (in cm) of the eyepiece is

A charge of 4 μC is placed in a uniform electric field of intensity 100N/C. The force acting on the charge is

A voltameter has internal resistance r ohms and range V volts.The value of resistance used in series to convert it into a voltmeter of range 4V volts is

The crictical angle for light going from a medium in which wavelength is 4000A0 to medium in which wavelength is 6000A0

A juggler maintains four balls on motion, making each inturn rise to a height 20m from his hand. Where will the other three balls be at the instant when the fourth one is just leaving the hand?

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 held 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 thegas in B is (γ = 5/3)

The natural frequency of a tuning fork p is 432 Hz. 3 beats/s are produced when tuning fork P and another tuning fork Q are sounded together. If P is loaded with wax, the number of beats increases to 5 beats/s. The frequency of Q is

A wire of length ‘l’ is bent into a circular loop of radius R and carries a current I. The magnetic field at the centre of the loop is 'B'. The same wire is now bent into a double loop of equal radii. If both loops carry the same current I and it is in the same direction, the magnetic field at the centre of the double loop will be

In Sun, the important source of energy is

The bridge of a sonometer is slightly displaced so that the length of wire is decreased by 0.5% and tension in the wire is increased by 1%.The fundamental frequency of wire

A liquid does not wet the solid surface if the angle of contact is

In two separate collisions, the coefficient of restitutions e1 and e2 are in the ratio 3:1. In the first collision the relative velocity of approach is twice the relative velocity of separation, then the ratio between relative velocity of approach and the relative velocity of separation in the second collision is

Percentage of mass lost during the fission of 42U235 approximately is

Keeping the banking angle sam,to increase the maximum speed with which a vehicle can travel on a curved road by 10 percent the radius of curvature of the road has to be changed from 20m to :

A clock which keeps correct time at 200C, is subjected to 400C. If coefficient of linear expansion of the pendulum is 12x 10-6 /0C. How much will it gain or lose time

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 couple acting on a magnet of length 10 cm placed in a uniform magnetic field of intensity 40 N/Am such that the axis of the magnet makes 450 with the field direction is √2/10 Nm. The pole strength of the magnet in Weber is :

In a transistor if IC/IE and IC/IB=β.If α varies between 20/21 and 100/101,then the value of β lies between

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

Two identical bodies have temperatures 2770C  and  670C. If the surroundings temperature is 270C, the ratio of loss of heats of the two bodies during the same interval of time is (approximately)

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 :

An ideal gas is subjected to a cyclic process involving four thermodynamic states; the amounts of heat (Q) and work (W) involved in each of these states are

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)

The magnetic induction at a point, distance x from the centre, on the axis of a circular current carrying coil is inversely proportional to (if x > > radius of coil) :

When a monochromatic light of frequency v is incident on a metal, stopping potential is V0. Frequency of the incident light for which stopping potential becomes 2V0 is

Two unknown resistance X and Y are connected to left and right gaps of a meter bridge and the balancing point is obtained at 80 cm from left. When a 10Ω resistance is connected in parallel to X, the balance point is 50 cm from left. The values of X and Y respectively are

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)

If in a Wheatstone bridge the battery and Galvanometer are interchanged, the condition for balance

8 beats are produced when two tuning forks A,B are made to vibrate together.The number of beats decreases to 5 beats/s when prongs of B are filed.If natural frequency of A is 282 Hz,the frequency of B before and after filling is

When a liquid is heated in copper vessel its Coefficient of apparent expansion is 6x10-6/0C.When the same liquid is heated in a steel vessel its coefficient of apparent expansion is 24x10-6/0C If coefficient of linear expansion for copper is 18x10-6/0C the coefficient of linear expansion for steel is

a spark is produced between two insulated surfaces maintained at a potential difference of 5 x 106 volt. The energy output is 10-5 J. The charge transferred during the spark is

A small amplitude progressive wave in a stretched string has a velocity of 10ms-1 and frequency of 100Hz.What is the phase differences, in radians between two points 5cm apart in the string?

Charges +50,+20,+30 and -100 nano coulomb are placed at the four corners of a square of side 5√2cm.The potential at the intersection point of diagonals is

If the magnitude of the intensity of a magnetic field at a distance x on the axial line and at a distance y on the equatorial line of a given dipole have the same value the ratio x : y is :

A cell in secondary circuit gives null deflection for 2.5 m length of potentiometer having 10 m length of wire If the length of the potentiometer wire is increased by 1 m without changing the cell in the primary, the position of the null point now is

The energy stored in a sphere of 10cm radius when the sphere is charged to a potential of 300 volt is

Four bulbs each marked 40 W. 250 V are connected in series with 250 V source. The total power output is

Two positive charges q1=4x10-6C and q2=9x10-6C are placed 10cm apart in air. The position of a third charge to be placed between them, such that there will be no resultant force on it 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

Two wires are fixed on a sonometer wire. Their tensions are in the ratio 8 : 1, the lengths in the ratio 36 : 35, the diameters in the ratio 4 : 1 and densities in the ratio 1 : 2. If the string of higher pitch has frequency of 360 Hz the frequency of the other string is(approximately)

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

The equation of wave is y=10 cos2π(t/0.02-x/10),where ‘t’ is in seconds an x in cm.The phase difference between two points separated by a distance of 5 cm at any instant is

The magnetic induction and the intensity of magnetic field inside an iron core of an electromagnet are 1 Wb m-2 and 150 Am-1 respectively. The relative permeability of iron is :(μ0=4π x 10-7 henry/m)

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)

A mass of 12 kg at rest explodes into two pieces of masses 4 kg and 8 kg which move in opposite directions. If the velocity of 8 kg piece is 6 m/s, then the kinetic energy of the other piece is (in joule):

A ball ‘A’of mass ‘m’ moving along positive x-direction with kinetic energy ‘K’ and momentum P undergoes elastic head on collision with a stationary ball B of mass ‘M’ After collision the ball A moves along negative X-direction with kinetic energy K/9,Final momentum of B 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

The current decays from 5A to 2A in 0.01s in a coil. The emf induced in a coil nearby it is 30V. The mutual inductance between the coils is

An insulated cylindrical vessel filled with an insulated piston of negligible weight and negligible thickness at the midpoint of the vessel. The cylinder contains a gas at 0oC. When the gas is heated to 100oC, the piston moves through a length of 5 cm. Length of the cylindrical vessel in cm is

The frequency of a tuning fork A is 2% greater than that of standard fork K.The frequency of another tuning fork B is 3% less than K.When A and B are vibrated together 6 beats per second are heard per second. The frequencies of A and B are

The focal length of a lens of dispersive power 0.45 which should be placed in contact with a convex lens of focal length 84 cm and dispersive power 0.21 to make the achromatic combination from the two lenses, in cm is

A pyknometer weight 40 g when empty and 1040 g when filled with mercury at 00C On heating to 1000C, 10 g of mercury overflows. If the coefficient of real expansion of mercury is 0.00020C the coefficient of expansion of glass is :

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.

If the critical angle of medium is 300. Then the polarizing angle for that medium is

An observer to moving away from a source of sound of frequency 100 Hz at a speed of 33 m/s. If the speed of the sound in air is 330 m/s and the observed frequency is

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 8N, it is in resonance with first overtone of the closed tube.The initial tension in the wire is

The refractive index of the material of a double convex lens is 1.5 and its focal length is 5 cm. If the radii of curvature are equal, the value of the radius of curvature (in cm) is

A potentiometer having a 4m long wire is connected to the terminals of a battery of constant output voltage. A Leclanche cell has a balancing length of 1m. If the length of the potentiometer wire is increased by 1m, then the position of the null point is

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

A stretched wire of some length under a tension is vibrating with its fundamental frequency. Its length is decreased by 45% and tension is increased by 21%.Now its fundamental frequency

In a hall a person receives direct sound from a source 120m away. He also receives waves from the same source which reach him after being reflected from the 25m high ceiling at a point midway between them. The two waves interfere constructively for wavelengths (in metre) of

The extension of a wire by application of a load is 0.3 cm.The extension in a wire of same material, but of double the length and half the radius of cross-section, by the same load will be, in cm :

An air bubble of radius 1 cm rises from the bottom portion through a liquid of density 1.5 g/cc at a constant speed of 0.25 cms-1. If the density of air is neglected, the coefficient of viscosity of the liquid is approximately, (In Pas) :

The temperature of 5 moles of a gas at constant volume is changed from 1000C to1200C The change In internal energy is 80J. The total heat capacity of the gas at constant volume will be in J/K is

The objective and eyepiece of an astronomical telescope are double convex lenses with refractive index 1.5. When the telescope is adjusted to infinity, the separation between the two lenses is 16 cm. If the space between the lenses is now filled with water and again telescope is adjusted for infinity, then the present separation between the lenses is

The difference between volume and pressure coefficients of an ideal gas is :

A vessel is filled with an ideal gas at a pressure of 10 atmosphere and temperature 270C. Half of the mass of the gas is removed from the vessel and temperature of the remaining gas is increased to 870C.Then the pressure of the gas in the vessel will be

A. ball of mass m moving with a velocity V*collides head on elastically with another of the same mass m but moving with a - V  (in the opposite direction). After the collision :

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

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)

A source of sound vibrating with a frequency 510Hz is in between a stationary observer and a fort wall, if source is moving towards observer with velocity 3m/s, the number of beats produced by the observer is (velocity of sound in air is 340m/s)

A rod with linear charge density λ is bent in the shape of circular ring.The electric potential at the centre of the circular ring is

Two parallel rails of a railway track insulated from each other and with the ground are connected to a millivoltmeter. The distance between the rails is one meter. A train is traveling with a velocity of 72 km/h along the track. The reading of the milli-voltmeter (in mV) is (Vertical component of the earth'smagnetic induction is 2 x 10-5 T)

If two identical bar magnets, each of length l, pole strength m and magnetic moment  M are placed perpendicular to each other with their unlike poles in contact, the magnetic moment of the combination is :

Photoelectric current can be increased by using :

A body of mass 5 kg makes an elastic collision with another body at rest and continues to move in the original direction after collision with a velocity equal to 1/10th  of its original velocity. Then the mass of the second body is

A 100 PFcapacitor is charged to a potential difference of 24V.It is connected to an uncharged capacitor 20PF.what will be the new potential difference across 100PF capacitor

The coil in a MCG has an area of 4cm2 and 500 turns.The intensity of magnetic induction is 2T.when a current of 10-4A is passed through it,the deflection is 200.The couple per unit twist is(N-m)

An ideal transformer has 400 turns in the primary and 200 turns in the secondary. If the primary connected to a 12V battery, then the secondary voltage 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)

Charge 20,30,-40 and 50 μC are at the corners of a square of 10cm. The field at the point of intersection of the diagonals is

A wire carrying a current of 140 ampere is bent into the form of a circle of radius 6cm.The flux density at a distance of 8 cm on the axis passing through the centre of the coil and perpendicular to its plane is(in wb/m2(approximately))

Un polarized light of intensity I0 is incident on a polarizer and the emerging light strikes a second polarizing filter with its axis at 450 to that of the first.The intensity of the emerging beam

A proton of mass m charge e is released from rest in a uniform electric field of strength E.The time taken by it to travel a distance d in the field is

A galvanometer of resistance 20Ω is to be shunted so that only 1% of the current passes through it. Shunt connected is

A force of 5 N making an angle 8 with the horizontal acting on an object displaces it by 0.4 m along the horizontal direction. If the object gains kinetic energy of 1 J the horizontal component of the force is :

In a meterbridge experiment,the balance length is 40cm.the resistance in the gap opposite to this length of wire is 8 ohm.The resistance in the other gap 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

A cylindrical resonance tube open at both ends has a fundamental frequency “f’ in air.If half of the length is dipped vertically in water,the fundamental frequency of the air column will be

In a coil of area 10cm2 and 10 turns with magnetic field directed perpendicular to the plane and is changing at the rate of 108 gauss/second.The resistance of the coil is 20Ω.The current in the coil will be