Basics electronics. part - 2

11. Which class of amplifiers operates with least distortion?

A. class A

B. class B

C. class C

D. class D

12. Which of the following transducers is classified as an active transducer?

A. Metallic strain gauge

B. Capacitive micro phone

C. L.V.D.T.

D. Piezo electric transducer

13. In a symbol of transistor, the sign of arrow show

A. Emitter

B. Base

C. Collector

D. Base and collector

14. When a transistor is used as a switch its operation is confined in

A. Cut-off region

B. Saturation region

C. Active region

D. Both A and B

15. α is a

A. small signal voltage gain of a CE transistor

B. large signal current gain of a CE transistor

C. large signal voltage gain of a CE transistor

D. small signal current gain of a CB transistor

16. A thyristor (SCR) is a

A. current controlled device

B. bilateral device

C. voltage control device

D. all of the above

17. After triggering an SCR, the gate pulse is removed, the current in SCR will

A. remain the same

B. immediately fall to zero

C. rise up

D. rise a little and fall to zero

18. When transistor is operating an active region

A. Collector junction is forward biased

B. Collector junction is reverse biased

C. Both collector and emitter junction are reverse biased

D. Both collector and emitter junctions are forward biased

19. In comparison with the turn-on time the turn-off time of a thyristor is

A. Lesser

B. Equal

C. Larger

D. All of these

20. In a mercury arc rectifier _____ flow from anode to cathode

A. Ions

B. Electrons

C. Ions and electrons

D. Any of the above