WBJEE Physics Test - 13 - JEE MCQ

In which case there is maximum extension in the wire, if same force is applied on each wire

The induced e.m.f. produced in the primary and secondary coils is 2 mV and 5 mV respectively. If the rate of change of current is 20 A-s^-1, then coefficient of mutual induction of the secondary coil is

The distance between the plates of a condenser is reduced to 1/4 th and the space between the plates is filled up by a medium of dielectric constant (K) 2.8. The capacity is increases by

A cyclotron is accelerating proton, where the applied magnetic field is 2 T, the potential gap is 100 KV, then how much turn the proton has to move between the dees to acquire a kinetic energy 20 Me V

At the magnetic poles of the earth, a compass needle will be

A block of mass M is pulled along a horizontal frictionless surface by a rope of mass m. If a force P is applied at the free end of the rope, then force exerted by the rope on the block is

A space ship is launched into a circular orbit of radius R close to surface of earth. The additional velocity to be imparted to the space ship in the orbit to overcome the earth's gravitational pull is [g - acceleration due to gravity]

A long straight conductor carries an electric current of 2A. The magnetic induction at a perpendicular distance of 5m from the wire is (μ₀ = 4π x10^-7 Hm^-1)

Observers on tenth, fifth and ground floor of a tall building measure the velocity of a certain rain drop by an accurate method. The velocity of rain drop measured by three observers is found to be the same. This is because the gravitational force

A charged particle of mass 5 x 10^-6 Kg is held stationary in space by placing it in an electric field of strength 10⁶ N C^-1 directed vertically downwards. The charge on the particle is g = 10 ms^-2

The relation between time 't' and distance 'x' is: t = ax² + bx; where a and b are constants. The acceleration is

For a projectile, the ratio of maximum height reached to the square of flight time is (g = 10 ms^-2)

Two bodies of mass 10 kg and 5 kg moving in concentric orbits of radii R and r such that their periods are the same. Then the ratio between their centripetal acceleration is

Substances which have identical chemical properties but differ in atomic weight are called

The equation of a simple harmonic motion is x=0.34 cos (3000 t+0.74) where and t are in mm and s respectively. The frequency of the motion is

The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillating bob gets suddenly unplugged. During the observation, till water is coming out, the time period of oscillation would

A wheel having moment of inertia 2 kg-m² about its vertical axis, rotates at the rate of 60 rev-min^-1 about this axis. The torque, which can stop the wheel's rotation in one minute, would be

The moment of inertia of a uniform circular disc of radius 'R' and mass 'M' about an axis passing from the edge of the disc and normal to the disc is

To a germanium sample, traces of gallium are added as an impurity. The resultant sample would behaves like

When the conductivity of a semiconductor is only due to breaking of covalent bonds, the semiconductor is called

If m is the mass, θ is temp. and 's' is specific heat, then thermal capacity k is given by

An air bubble is contained inside water. It behaves as a

First law of thermodynamics is a special case of

Which of the following pair does not have similar dimensions

A vector b=3i+4k, is equal to the sum of vectors B₁ and B₂ where B₁ is parallel to A=i+j and vector B₂ is perpendicular to A. Then B₁=

The superposition principle applies to

On stretching a spring by 0.1 m, a elastic potential energy of 5 J is stored in it. The force constant of the spring is