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

Question : 6

If a body is positively charged, then it has

a) excess of protons

b) deficiency of electrons

c) excess of electrons

d) deficiency of neutrons

Question : 7 [MPPCS (Pre) 1993]

Which gas is filled in normal tubelights?

a) Mercury vapour with argon

b) Sodium vapour with argon

c) Sodium vapour with neon

d) Mercury vapour with neon

Question : 8

Regarding a semiconductor which one of the following is wrong?

a) There are no free electrons at 0K

b) The number of free electrons increases with rise of temperature

c) There are no free electrons at room temperature

d) The charge carriers are electrons and holes

Question : 9

The energy band gap is maximum in

a) superconductors

b) insulators

c) metals

d) semiconductors

Question : 10 [PSC (Pre) 2019]

A fuse is used in main electric supply as a safety device. Which one of the following statements about the fuse is correct?

a) It must have a low melting point

b) It is connected in parallel with the main switch

c) It is made mainly from silver alloys

d) It must have a very high resistance