The coefficient of areal expansion of a material is 1.6 x 10^-5 K^-1. Which one of the following gives the value of coefficient of volume expansion of this material?

• 0.8 x 10^-5 K^-1

• 2.4 x 10^-5 K^-1

• 3.2 x 10^-5 K^-1

• 4.8 x 10^-5 K^-1

The refractive indices of two media are denoted by n₁ and n₂ and the velocities of light in these two media are respectively v₁ and v₂. If n₂/n₁ is 1.5, which one of the following statements is correct?

• v₁ is 1.5 times v₂

• v₂ is 1.5 times v₁

• v₁ is equal v₂

• v₁ is 3 times v₂

Which one of the following statements is correct for a plane mirror?

• Its focal length is zero

• The size of the image of an object placed in front of the mirror is slightly less than that of the object

• The image is virtual, erect and laterally inverted

• Its focal length is 200 cm

An object is placed in front of a convex mirror. Which one of the following statements is correct?

• It will never form an inverted image

• The image moves towards the focus when the object moves towards the mirror

• Depending on the position of the object with respect to the mirror, the image can be inverted and real

• The size of the image becomes larger than that of the object when the object is placed at a distance equal to half the focal length

A circular coil of radius R having N number of turns carries a steady current I. The magnetic induction at the centre of thecoil is 0.1 tesla. If the number of turns is doubled and the radius is halved, which one of the, following will be the cor ect value for the magnetic induction at the centre of the coil?

• 0.05 tesla

• 0.2 tesla

• 0.4 tesla

• 0.8 tesla

Which one of the following statements is correct?

• Any energy transfer that does not involve temperature difference in some way is not heat.

• Any energy transfer always requires a temperature difference.

• On heating the length and volume of the object remain exactly the same.

• Whenever there is a temperature difference, heat is the only way of energy transfer.

If T is the time period of an oscillating pendulum, which one of the following statements is NOT correct?

• The motion repeats after time T only once

• T is the least time after which motion repeats itself

• The motion repeats itself after nT, where n is a positive integer

• T remains the same only for small angular displacements

48.

If an object moves with constant velocity, then which one of the following statements is NOT correct?

• Its motion is along a straight line

• Its speed changes with time

• Its acceleration is zero

• Its displacement increases linearly with time

An object is moving with uniform acceleration a. Its initial velocity is u and after time t its velocity is v. The equation of its motion is v = u + at. The velocity (along y-axis) time (along x-axis) graph shall be a straight line

• passing through origin

• with x-intercept u

• with y-intercept u

• with slope u

What is the net force experienced by a bar magnet plated in a uniform magnetic field?

• Zero

• Depends upon length of the magnet

• Never zero

• Depends upon temperature