set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

Two pieces of metallic wire having equal lengths and equal volume placed in air have different resistances. The two wires must

a) be of different materials

b) have different cross-sections

c) have different temperatures

d) be of same density

Question : 2

The temperature of the filament of lighted electric bulb is generally

a) 2000°C to 2500°C

b) 100°C to 500°C

c) 1000°C to 1500°C

d) 3000°C to 3500°C

Question : 3

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 : 4

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 : 5

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 : 6

In a transistor

a) collector is more highly doped than emitter

b) both are equally doped

c) emitter is more highly doped than collector

d) None of the above