Basics electronics. Part – 1

1. The output voltage in an operational amplifier is out of phase from the input voltage by an angle of ;

A. 90⁰

B. 60⁰

C. 120⁰

D. 180⁰

2. An R-C coupled circuit is a high pass filter for,

A. Pulsating DC voltage

B. Low frequency AC voltage

C. DC voltage

D. None of these

3. Which of the following terminals does not belong to the MOSFET?

A. Base

B. Source

C. Gate

D. Drain

4. The load voltage of a chopper can be controlled by varying the

A. Firing angle

B. Extinction angle

C. Duty cycle

D. Reactor position

5. In a SCR based converter, the freewheeling diode is used to

A. Add to the conduction current of thyristors

B. Conduct current during the OFF period of the SCR

C. Protect the SCR by providing a shunt path

D. Oppose the SCR conduction

6. In a step down chopper, if Vs = 100v and the chopper is operated at a duty cycle of 75% . Find the output voltage.

A. 25V

B. 10V

C. 100V

D. 75V

7. In an ideal op-amp the output impedance is

A. Infinite

B. 50 ohm

C. Zero

D. 100 ohm

8. What is an ideal value of attenuation for the frequencies in pass band especially for a cascade configuration?

A. Zero

B. Unity

C. Unpredictable

D. Infinity

9. In a NPN transistor if the emitter junction  is reverse biased and collector junction is also reverse biased, the transistor will operate in

A. Cut-off region

B. Saturation region

C. Inverted region

D. Active region

10. The input and output signals for CE amplifier are always

A. equal

B. negative

C. out of phase

D. in phase