Basic Electronics MCQ Question and Answer
Basic Electronics MCQ Question and Answer
11. A piece of copper and other of germanium are cooled from the room temperature to 80K, then
- resistance of each will increase
- resistance of copper will decrease
- the resistance of copper will increase while that of germanium will decrease
- the resistance of copper will decrease while that of germanium will increase
12. Diamond is very hard because ?
- it is covalent solid
- it has large cohesive energy
- high melting point
- insoluble in all solvents
13. The part of the transistor which is heavily doped to produce large number of majority carriers is
- emitter
- base
- collector
- any of the above depending upon the nature of transistor
14. An Oscillator is nothing but an amplifier with
- positive, feedback
- negative feedback
- large gain
- no feedback
15. When a P-N junction diode is reverse biased the flow of current across the junction is mainly due to
- diffusion of charge
- drift charges
- depends on the nature o material
- both drift and diffusion of charges
16. Which of the following, when added as an impurity, into the silicon, produces n-type semi conductor
- Phosphorous
- Aluminium
- Magnesium
- both ‘b’ and ‘c’
17. The current gain for a transistor working as common-base amplifier is 0.96. If the emitter current is 7.2 mA, then the base current is
- 0.29mA
- 0.35mA
- 0.39 mA
- 0.43 mA
18. When a n-p-n transistor is used as an amplifier then ?
- the electrons flow from emitter to collector
- the holes flow from emitter to collector
- the electrons flow from collector to emitter
- the electrons flow from battery to emitter
19. When arsenic is added as an impurity to silicon, the resulting material is?
- n-type semiconductor
- p-type semiconductor
- n-type conductor
- Insulator
20. To obtain a p-type germanium semiconductor,it must be doped with ?
- arsenic
- antimony
- indium
- phosphorus