Start Test

A uniform wire of length 20m and weighing 5kg hangs vertically. If g=10m/s2,then the speed of transverse waves at the middle of the wire is

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:

If the angle of minimum deviation produced by an equilateral prosm is 300, the refractive index of material of prism is

Two long straight conductors are held parallel to each other at a distance 0.3 m. 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 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

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

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

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

A dielectric of thickness 5cm and dielectric constant 10 is introduced between the plates of a parallel plate capacitor having plate area 500 sq.cm and separation between the plates 10cm.The capacitance of the capacitor with dielectric slab is(ε0=8.8x10-12/N-m2)

An n-p-n transistor power amplifier in C-E configuration gives :

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

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

A body is sliding down on a rough inclined plane of inclination 45. The time taken by it to slide down on the rough inclined plane is 3 times the time taken by the body to slide down the smooth inclined plane of same inclination and length. The co-efficient of friction between the rough inclined plane and the body is

Two strings x and y on a Veena playing the same note are slightly out of tune and produce 6 beats per second. The tension in x is slightly decreased and it is found tha the beats fall to 3 per second. If the original frequency of x is 324 Hz, the frequency of y 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 body is projected vertically upwards from the surface of the earth with a velocity equal to half the escape velocity. If R is the radius of the earth, maximum height attained by the body from the surface of the earth is

The spheres of different materials one with double the radius and one-fourth wall thickness of the other are filled with ice.If the time taken for complete melting of ice in the larger radius one is 25 minutes and that for smaller one is 25 minutes,the ratio of thermal conductivities of materials of larger sphere to smaller sphere is:

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 capacitor of capacity C is charged to a potential V.It is charged and isolated.Then distance between the plates is halved and then half the distance between them is filled with a metal slab.Then the capacitor

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

Two bar magnets A, B are placed one over the other and are allowed to vibrate in a vibration magnetometer. They make 20 oscillations per minute when the similar poles of A and B are on the same side, while they make 15 oscillations per minute when their opposite poles lie on the same side. If MA and MB are the magnetic moments of A and B and if MA > MB, the ratio of MA and MB 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 simple microscope is rated 5x for a normal relaxed eye.what will be its magnifying power for a far sighted man whose near point is 40 cm.

An observer is standing 500 m away from a vertical hill. Starting between the observer and the hill, a police van sounding a siren of frequency 1000 Hz moves towards the hill with a uniform speed. If the frequency of the sound heard directly from the siren is 970 Hz, the frequency of the sound heard after reflection from the hill (in Hz) is about, (velocity of sound = 330ms-1):

Two straight long parallel conductors carrying different currents are separated by a distance 20 cm in air such that force per unit length on each conductor is 5 x 10-3 N/m If the current in first conductor is 50 A then the current in the second conductor 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 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

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 uniform rod of length 8a and mass 6m lies on a smooth horizontal surface. Two point masses m and 2m moving in the same plane with speed 2 v and v repectively strike the rod perpendicularly at distances a and 2a from the mid point of the rod in the opposite directions and stick to the rod. The angular velocity of the system immediately after the collision 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

Two concentric circular coils A and B have radii 25cm and 15cm and carry currents 10A and 15A respectively.A has 24 turns and B has 18 turns.The direction of currents are in opposite order.The magnetic induction at the common centre of the coil is

A whistle of frequency 540 Hz rotates in a horizontal circle of radius 2 m at an angular speed of 15 rad/s. The highest frequency heard by a listener at rest with respect to the centre of circle (velocity of sound in air = 330 ms-1)

A sound wave passing through an ideal gas at NTP produces a pressure change of 0.001 dyne/cm2 during adiabatic compression. The corresponding change in temperature (γ=1.5 for the gas and atmospheric pressure is 1.013 x106 dynes/cm2) is

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

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

A Tuning fork A produces 6 beats per second with another fork B.On loading B with a little wax,it produces 5 beats per second with A If the frequency of A is 256 Hz,the frequency of B is

When an air bubble of radius r rises from the bottom to the surface of a lake. Its radius becomes 5r/4 (the pressure of the atmosphere is equal to the 10 m height to water column). If the temperature is constant and the surface tension is neglected the depth of the lake is

The radioactivity of a sample is 'X' at a time 't1' and ‘Y’ at a time 't2'. If the mean life time of the specimen is г the number of atoms that have disintegrated in the time interval (t1 – t2) is

A given mass of a gas is compressed isothermally until its pressure is doubled. It is then allowed to expand adiabatically until its original volume is restored and its pressure is then found to be 0.75 of its initial pressure.The ratio of the specific heats of the gas is approximately

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

In a metre bridge experiment, the ratio of the left gap resistance to right gap resistance is 2 : 3, the balance point from left is

The coils in two moving coil galvanometer have their areas in the ratio of 2:3 and number of turns in the ratio 4:5. These two coils carry the same current and are situated in the same field. The deflections produced by these coil will be in the ratio of

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

The natural frequency of an I.-C circuit is 1,25,000 cycle/s. Then the capacitor C is replaced by another capacitor with a dielectric medium of dielectric constant K. In this case, the frequency decreases by 25 kHz. The value of K is

Two satellites A and B go around the earth in a circular orbits at a height of RA and RB respectively from the surface of the earth. Assume the earth to be a uniform sphere of radius RE. The ratio of magnitudes of the velocities of the statellites VA/VB =

The difference between heats of reaction at constant pressure and at constant volume for the reaction 2C6H6(l)+15O2(g) → 12CO2(g)+6H2O(l) at 250C in KJ is

If the angle of minimum deviation produced by equilateral prism is 300.The refractive index of the prism is

A certain block weights 15N in air. But it weighs only 12N when completely immersed in water. When immersed in another liquid, it weighs 13N. The ratio of relative density of the block and the liquid

The potential energy of a proton is 3.2x10-18J at a particular point. The electric potential at this point 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)

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

A horizontal pipe of non-uniform cross-section allows water to flow through it with a velocity 1 ms-1 when pressure is 50 kPa at a point. If the velocity of flow has to be 2 ms-1 at some other point, the pressure at that point should be

A body of weight "64N" is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards, if the coefficients of static and dynamic friction are 0.6 and 0.4 respectively, the acceleration of the body is: (acceleration due to gravity = g)

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

The number of turns in primary and secondary coils of a transformer is 50 and 200. If the current in the primary coil is 4 A, then the current in the secondary coil is

A tension of 22 N is applied to a copper wire of cross-sectional area 0.02 cm2 Young’s modulus of copper is 1.1x1011 N/m2and Poisson’s ratio 0.32. The decrease in cross sectional area will be

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

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

The photoelectric work function of a metal surface is 2eV.When light of frequency 1.5x1015Hz is incident on it,the maximum kinetic energy of the photo electrons approximately is

If 9.8 gms of H2SO4 is neutralized exactly with strong alkali ,the heat evolved is(?H of neutralization is 13.6 K.cal)

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

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]

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 the platform with a speed of 4 ms-1. Another train is leaving the platform with the same speed in opposite direction. The velocity of sound is 320ms-1. If both the trains sound their whistles at frequency 240 Hz, the number of beats heard per second by the passenger of the first train will be (nearly)

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 vehicle sounding a whistle of frequency 256 Hz is moving on a straight road, towards a hill with a velocity of 10 ms-1 . The number of beats per second observed by a person travelling in the vehicle is : (Velocity of sound =330 ms-1)

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 :

If the focal length of a lens for marginal rays and paraxial rays are 12.5cm and 13cn respectively, the longitudinal spherical aberration is

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

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

A whistle of frequency 540Hz rotates in a horizontal circle of radius 2m at an angular speed of 15rad/s. The highest frequency heard by a listener away from the circle at rest with respect to the centre of circle (velocity of sound in air=330m/s)

The magnetic induction at the centre due to motion of electron in first Bohr orbit is B. magnetic filed due to the motion of electron in second Bohr orbit at the centre will bw

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 :

A transverse wave propagating on a stretched string of linear density 3 x 10-4 kg m-1 is represented by the equation y = 0.2sin (1.5x - 60t) where x is in meters and t is in seconds. The tension in the string (in newton) is

The focal length of the lenses of an astronomical telescope are 50 cm and 5cm. The length of the telescope when the image is formed at the least distance of distinct vision is:

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)

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

A stone is projected in air. Its time of flight is 3s and the range is 150m. Maximum height reached by the stone is: (g = 10 ms-2)

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 sonometer wire produces 2 beats per second with a tuning fork, when the length of the wire is either 102cm or 1004cm.The frequency of the tuning fork 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

A segment of wire vibrates with a fundamental frequency of 450 Hz under a tension of 9 kg wt. Then tension at which the fundamental frequency of the same wire becomes 900 Hz is

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

An auditorium has volume of 105m3 and surface area of absorption 2 x 104m2.Its average absorption coefficient is 0.2 .The reverberation time of the auditorium in seconds is

For the system S(s)+O2(g)→SO2(g)?

Two charges of 10μC and -90μC are separated by a distance of 24cm.Electrostatic field strength from the smaller charge is zero at a distance of

The velocity of a listener who is moving away from a stationary source of sound such that the listener notices 5% apparent decrease in frequency of sound is(Velocity of sound in air=340ms-1)

Apparent frequency of sound is 505 Hz when the listener is approaching a stationary source of sound with a velocity 1% of the velocity of sound in air. The actual frequency of sound is

A bar-magnet of moment of inertia 49 x 10-2 kg-m2 vibrates in a magnetic field of induction 0.5 x10-4 T. The time period of vibration is 8.8 s. The magnetic moment of the bar magnet is

In a potentiometer experiment, when a resistance of 10 ohm is connected in parallel to the cell in secondary circuit , the balancing length is 350 cm. when 10 ohm resistance is replaced by 20 ohm resistance, the balancing length becomes 420 cm.The internal resistance of the cell in secondary circuit is

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)

Two wires A and B,made of same material and having their lengths in the ratio 6:1 are connected in series.The potential differences across the wires are 3V and 2V respectively.If rA and rB the radii of A and B respectively,then rA/rB is

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

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

Two strings A and B of lengths. LA = 80 cm and LB = x cm respectively are used separately in a sonometer. The ratio of their densities {dA/dB) is 0.81. The diameter of B is one-half that of A. If the strings have the same tension and fundamental frequency the value of x is :

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

Photoelectric current can be increased by using :

The temperature of the system decreases in the process of

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

Note:

- Click the 'Submit Test' button given in the bottom of this page to Submit your answers.
- Test will be submitted automatically if the time expired.
- Don't refresh the page.