electric current and magnetism - Category wise Question and Answer Practice Test with Solutions

Question : 1

Which of the statements is true for p-type semiconductos?

a) Electrons are minority carriers and pentavalent atoms are the dopants.

b) Holes are minority carriers and pentavalent atoms are the dopants.

c) Electrons are majority carriers and trivalent atoms are the dopants.

d) Holes are majority carriers and trivalent atoms are the dopants.

Question : 2

When a ferromagnetic material is heated to temperature above its Curie temperature, the material:

a) behaves like a diamagnetic material

b) is permanently magnetized

c) remains ferromagnetic

d) behaves like a paramagnetic material

Question : 3

Match list-I with list -II:

a) A – 4 ; B – 3 ; C – 2 ; D – 1

b) A – 3 ; B – 1 ; C – 2 ; D – 4

c) A – 4 ; B – 2 ; C – 3 ; D – 1

d) A – 3 ; B – 4 ; C – 1 ; D – 2

Question : 4

The frequency of A.C. mains in India is

a) 50 c/s

b) 60 c/s

c) 30 c/s

d) 120 c/s

Question : 5 [NDA]

If the focal length of the biconvex lens is 25 cm, then the power of the lens will be

a) + 0.04 dioptre

b) + 4 dioptre

c) – 4 dioptre

d) – 0.04 dioptre