The output signal voltage and current of a power amplifier are 5V and 200 mA; the values being r.m.s. What is the power output ?

The output transformer used in a power amplifier is a _____________ transformer?

A. 1:1 ratio

B. Step-up

C. Step-down

D. None of the above

The pulsating d.c. applied to power amplifier causes________________?

A. Burning of transistor

B. Hum in the circuit

C. Excessive forward voltage

D. None of the above

If the gain versus frequency curve of a transistor amplifier is not flat, then there is distortion ?

A. Amplitude

B. Intermodulation

C. Frequency

D. None of the above

If the power rating of a transistor is 1W and collector current is 100mA, then maximum allowable collector voltage is________________?

A. 1V

B. 100V

C. 20V

D. 10V

What will be the collector efficiency of a power amplifier having zero signal power dissipation of 5 watts and a.c. power output of 2 watts ?

A. 20%

B. 80%

C. 40%

D. 50%