set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

If a body is charged by rubbing it, its weight

a) increases slightly

b) decreases slightly

c) remains precisely constant

d) may increase slightly or may decrease slightly

Question : 2

Five bulbs each of 100 watt capacity in a tunnel are illuminated continuously for twenty hours. The consumption of electricity will be

a) Ten units

b) One unit

c) Two units

d) Twenty units

Question : 3

Small drops of the same size are charged to V volts each. If n such drops coalesce to form a single large drop, its potential will be

a) nV

b) $n^{2/3}$V

c) $n^{1/3}$V

d) $n^{–1}$V

Question : 4

What is the order of magnitude of electric resistance of the human body (dry)?

a) $10^6$ ohm

b) $10^2$ ohm

c) $10^4$ ohm

d) $10^8$ ohm

Question : 5

Application of a forward bias to a p–n junction

a) increases the potential difference across the depletion zone.

b) increases the number of donors on the n side.

c) widens the depletion zone.

d) increases the electric field in the depletion zone.

Question : 6

n-p-n transistors are preferred to p-n-p transistors because:

a) they have low dissipation energy

b) they are capable of handling large power

c) they have low cost

d) electrons have high mobility than holes and hence high mobility of energy