A to Z Exams

The energy stored in a capacitor is given by (V = voltage, C = capacitance. q= charge)

A proton, a deuteron (nucleus of 1H2) and an α-particle with same kinetic energy enter a region of uniform magnetic field moving at right angles to the field. The ratio of the radii of their circular  paths is :

Two identical metal spheres possess +60C and -20C of charges.They are brought in contacts and then separated by 10cm.The force between them is

The volume of a cinema theatre is 100mx60mx20m and total acoustic absorption in it is 6800metric sabine.The reverberation time in that theatre is

A force is experienced by cathode rays when they pass through uniform electric field

Temperature of cold junction in a thermo- couple is 100C and neutral temperature is 2700C, then the temperature of inversion is

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

The maximum tension a rope can withstand is 60 kg wt The ratio of maximum acceleration with which two boys of masses 20 kg and 30 kg can climb up the rope at the same time is

A magnifying glass is made of a combination of convergent lens of power +20 diopters and a divergent lens of power -4 diopters .If the image is formed atleast distance of distinct vision (25cm), the magnifying power is

Calculate enthalpy for formation of ethylene from the following dataI. C(graphite)  + O2(g) ----->  CO2(g)   ∆H = 393.5kjII. H2(g) + (1/2) O2(g) ---------->  H2O(l) ∆H = -286.2kjIII.C2H4(g) + 3O2(g) ----------> 2CO2(g) + 2H2O(l)   ∆H = -1410.8kj

A body projected vertically upwards crosses a point twice in its journey at a height h just after t1 and t2 seconds. Maximum height reached by the body is

A body is thrown vertically upward with an initial velocity u reaches maximum height in 6 sec.The ratio of distance travelled by the body in the first and seventh second is :

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)    

Acurrent of 5Ais flowing through along straight copper wire.the ratio of the magnetic inductions at distance of 1.0 cm and 2.0cm from the is

A certain number of beats are heard when two tuning forks of natural frequencies n1 and n2 are sounded together. The number of beats heard when one of the forks is loaded :

Thomson coefficient of a conductor is 10μV/K.The two ends of it are kept at 500C and 600C respectively.Amount of heat absorbed by the conductor when a charge of 10C flows through it is

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 :

Two long straight conductors are held parallel to each other at a distance 0.3m.If the conductors carry currents 2A and 8A in opposite directions,the distance of the neutral point from the conductor carrying smaller current is

A somometer wire vibrates with frequency of 500 Hz when the tension is T1 and with a frequency of 400 Hz when the tension is T2.Its frequency of vibration for a tension(T1-T2) is (in Hz)

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 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

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 cell of emf 2V and negligible resistance is connected in series with a resistance of 5 ohm,and a potentiometer wire of resistance 10 ohm.what is the potential drop per cm if the length of the potentiometer wire is 10m.The emf of a cell which is balanced by 750cm long wire 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

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

When cold junction is at 00C variation of thermo emf(e) of Fe-Cu thermo couple with temperature of hot junction t is given as e=14t-0.02t2.Its neutral temperature is

The speed of transverse vibrations in a stretched string is 700cm/s.If the string is 2m long,the frequency with which it resonates in fundamental mode is

Neutral temperature of a thermo couple is 2500C.If the value of’a’ is 15μv/0C,the value of ‘b’ is

X-rays of energy 50 KeV are scattered from a carbon target. The scattered rays are detected at 900 from the incident beam. the percentage change in wave length approximately [mo=9.0x10-31kg, c=3x108 m/sec] is

The charge stored in a capacitor is 20μC and the potential difference across the plates is 500V,its capacity is

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

A plastic tube containing few stones is floating in a tank of water. If the stones are unloaded, the water level :

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

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

With a standard rectangular bar magnet of length (l), breadth (b; b < < l) and magnetic moment M, the time period of the magnet in a vibration magnetometer is 4 s. If the magnet is cut normal to its length into four equal pieces, the time period (in seconds) with one of the pieces is :

The objective of a telescope has focal length 120cma and diameter 5cm.The focal length of the eye piece is 2cm.The magnifying power of the telescope for distant object is

A solid wooden block resting on a frictionless surface is hit by a bullet. The bullet gets embedded. During this process:

A capacitor of 8 μF is charged to a potential of 1000V. The energy stored in the capacitor is

Under minimum deviation condition in a prism, if a ray is incident at an angle of 300. The angle between the emergent ray and the second refracting surface of the prism is: ( Angle of prism = 600)

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

Two tuning forks of frequencies 250 and 256 Hz produce beats.If maximum is produced now,thus the minimum time after which minimum is produced at that same place

In Atwood’s machine, two masses 3 kg and 5 kg are connected by a light string which passes over a frictionless pulley. The support of the pulley is attached to the ceiling of a compartment of a train. If the train moves in a horizontal direction with a constant acceleration 8 ms-2 the tension in the string in Newtons is(g=10ms-2)

The pole strength of a 12 cm long bar magnet is 2.0 A-m. The magnetic induction at a point 10 cm away from the centre of the magnet on the axial line is (μ0/4∏=10-7Hm-1)

A 4Ω resistor in series with 8Ωresistance are connected to 12 V supply.If another resistor of 8Ω is connected across the 8Ω resistor the current drawn from source would be

Two cylindrical conductors A and B of same metallic material have their diameters in the ratio 1 : 2 and lengths in the ratio 2 : 1. If the temperature difference between their ends is same, the ratio of heats conducted respectively by A and B per sec is:

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)

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

A person is in between two vertical mountains.The person fires a gun then hears the first echo from the nearby mountain in a time 3s and hears second echo from far mountain in a time 4s.The person hears the third echo after

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

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      

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

Two tuning forks A and B produce 6 beats per second when sounded together. When B is slightly loaded with wax the beats are reduced to 4 per second. If the frequency of A is 512 Hz the frequency of B 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

A bucket filled with water is tied to a rope of length 0.5 m and is rotated in a circular path in vertical plane. The least velocity it should have at the lowest point of circle so that water doesnot spill is, (g = 10 ms-2 )

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?

Fraunhofer lines are produced by the absorption of light in :

An aluminum (resistivity ρ = 2.2 x 10-8 Ω-m) wire of a diameter 1.4 mm is used to make a4Ω resistor. The length of the wire is

Photons of energy 2.0 eV and wavelength λ fall on a metal plate and release photoelectrons with a maximum velocity v.By decreasing X by 25% the maximum velocity of photoelectrons is doubled. The work function of the material of the metal plate,in eV is:

Magnetic field induction at the centre of a circular coil of radius 5 cm and carrying a current 0.9 A is (in S.I. units) (ε0 = absolute permittivity of air in S.I. units; velocity of light = 3 x 108 ms-1)

Two wires of the same material but of different diameters carry the same current I. If the ratio of their diameters is 2 : 1, then the corresponding ratio of their mean drift velocities will be

Two sources A and B are sending notes of frequency 680 Hz. A listener moves from A to B with a constant velocity V. If the speed of sound in air is 340 ms-1, what must be the value of V so that he hears 10 beats per second

An iron load of 2kg is suspended in air from the free end of a sonometer wire of length 1m.A tuning fork of frequency 256Hz is in resonance with 1/√14 times the length of the sonometer wire.If the load is immersed in water,the length of the wire in meter that will be in resonance with the same tuning fork is (specific gravity of iron=8)

When a wire of length 10 m is subjected to a force of 100 N along its length, the lateral strain produced is 0.01 x 10-3 m. The Poisson's ratio was found to be 0.4. if the area of cross-section of wire is 0.025 m2, its Young's modulus is

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

Two small angled prisms A and B deviate the blue rays by 70 and 90 and the red rays by 50 and 70 respectively. The prism which has a greater dispersive power is

Four resistors A,B,C and D form a Wheatstones bridge. The bridge is balanced when C = 100Ω .If A and B are interchanged, the bridge balances for C= 121Ω.The value of D 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

A convex lens of focal length 0.15m is made of a material of refractive index 3 / 2. When it is placed in a liquid, its focal length is increased by 0.225 m. The refractive index of the liquid is

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)

In the Young's double slit experiment, the intensities at two points P1, and P2 on the screen are respectively I1, and I2. If P1, is located at the centre of a bright fringe and P2 is located at a distance equal to a quarter of fringe width from P1 then I1/I2 is

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 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)

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))

Resistances are connected in the two gaps of a meter bridge.The balance point is 20cm from the zero end.When a 15Ω resistor is connected in series with the smaller resistance then the null point shifts to 40cm.the smaller resistance is

When a liquid in a glass vessel, is heated its apparent expansion is 10.30 x 10-4same liquid when heated in a metal its apparent expansion 10.06 x 10-4/0C. The coefficient of linear expansion of the metal is : (coefficient of linear expansion of glass = 9 x 10-6/0C):

Which one of the following statement is true ?

If the work done in stretching a wire by 1mm is 2J,the work necessary for stretching another wire of same material but with double radius of cross-section and half the length by 1mm(in joule) is:

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

Two unit negative charges are placed on a straight line. A positive charge q is placed exactly at the mid point between these unit charges. If the system of these three charges is in equilibrium, the value of q (inC) is

The rate constant of the reaction at temperature 200K is 10 times than the rate constant at 400K.The activation energy of the reaction is

Three point charges 1C, -2C and -2C are placed at the vertices of an equilateral triangle triangle of side 1 metre The work done by an external force to increase the separation of the charges to 2 metre in joule is : (ε0= permittivity of air)

If the angle of a prism is 600 and angle of minimum deviation is 400, then the angle of refraction in the prism will be

A glass tube 1.5m long and open at both ends, is immersed vertically in a water tank completely. A tuning fork of 600Hz is vibrated and kept at the upper end of tube and tube is gradually raised out of water.The total number of resonances heard before when the tube comes out of water, taking velocity of sound as 330m/sec. is

In Resonance Column experiment with a closed pipe, the first, second and third reso-nance lengths L1, L2, L3 respectively beat the relationship

A string in a musical instrument is 50 cm long and its fundamental frequency  is 270 Hz.If the desired frequency of 1000Hz is to be produced, the required string length is

Two positive charges 12μC and 10μC are initially separated by 10cm.The work done in bringing the two charges 4cm closer is

A car travels the first half of a distance between two places a speed of 30 km/hr and the second half of the distance a 50km/hr. The average speed of the car for the whole journey is

A primary coil and secondary coil are placed close to each other. A current, which changes at the rate of 25 amp in a millisecond, is present in the primary coil. If the mutual inductance is 92x10-6 Henries,then the value of induced emf in the secondary coil is

When a metal surface is illuminated by a light of wavelength 400 nm and 250 nm The maximum velocities of the photo electrons ejected are v and 2v respectively.The work function of the metal is : (h= Planck's constant, C= velocity of light in air)

A 2μF condenser is charged to 500 V and then the plates are joined through a resistance in joule is

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

Consider the two following statements A and B,and identify the correct choice given in the answers:A) In photovoltaic cells the photoelectric current produced is not proportional to the Intensity of Incident light (B) In gas filled photo emissive cells, the velocity of photo-electrons depends on the wavelength of the incident radiation

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:

Identify the increasing order of the angular velocities of the following :1.earth rotating about its own axis2.hour's hand of a clock3.second's hand of a clock4.flywheel of radius 2 m making 300 rpm

A bomb is dropped from an aircraft travelling horizontally at 150m/s at a height of 490m. The horizontal distance travelled by the bomb before it hits the ground is (in metre):

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

A 2 kg body and 3 kg body have equal momentum. If the kinetic energy of 3 kg body is 10 Joules, the kinetic energy of 2 kg body will be, (in joules) :

Indium impurity in germanium makes it into a

If the angle of a prism is 600 and angle of minimum deviations is 400, then the angle of refraction in the prism will be