set 9 MCQ Questions & Answers Detailed Explanation

Question : 1

Which one of the statements given below is not correct?

a) The degree to which the magnetic field can penetrate a medium is known as the relative permeability of the medium

b) A vertical plane passing through the axis of a freely suspended magnet is called the magnetic meridian

c) A vertical plan passing through the axis of rotation of the Earth is called the geographical meridian

d) The relative permeability is not a dimensionless quantity

Question : 2

Which of the following is an artificial magnet?

a) Magnetic needle

b) Bar magnet

c) Horse-shoe magnet

d) All of the above

Question : 3

Which one among the following is used to make periscope?

a) Plane mirror

b) Concave lens

c) Concave mirror

d) None of the above

Question : 4

When a forward bias is applied to a p-n junction, it

a) reduces the majority carrier current to zero.

b) lowers the potential barrier.

c) raises the potential barrier.

d) None of these

Question : 5

What gases are filled in fluorescent tube?

a) Mercury

b) Neon

c) Sodium

d) Mercury and neon

Question : 6

The current in the armature of a motor is reversed at every half cycle due to the action of a(n)

a) field coil

b) brush

c) armature

d) commutator