Power Ampliers

Cross Over distortion behavior is a characteristic of -

• Class A output stage

• Class B output stage

• Class AB output stage

• Common base output stage

A class A transformer coupled power amplifier is to deliver 10 W output. The power rating of transistor should not be less than

• 5 W

• 10 W

• 20 W

• 40 W

The dissipation at the collector is in the quiescent state & increases with excitation in case of -

• Class A series fed amplifier

• Class A transformer coupled Amplifier

• Class AB amplifier

• Class B amplifier

Which distortion is least objectionable in case audio amplifiers?

• Phase Distortion

• Frequency Distortion

• Harmonic distortion

• Inter- modulation distortion

A push pull amplifier balance out -

• odd harmonics

• Even harmonics

• both odd & even harmonics

• neither odd nor even harmonics

In class C power amplifier, the collector current exists for-

• 360^o of input signal

• 180^o of input signal

• more than 180^o of input signal

• less than 180^o off input signal

In push pull amplifier there occurs cancellation of -

• odd harmonics

• Even harmonics

• both odd & even harmonics

• neither odd nor even harmonics

Class AB operation is often used in large signal amplifier in order to-

• get maximum efficiency

• eliminate even harmonics

• overcome crossover distortion

• reduce collector dissipation

Which of the following are the main advantages of class B push pull power amplifier?

a) Even harmonics tend to cancel out at the output

b) More power output per transistor

c) Conversion efficiency can be as high as 78%

d) Absence of crossover distortion

select the correct answer as given below-

• a,b & c

• a,b & d

• a,c& d

• b,c& d

Where does the operating point of class B power amplifier lie?

• at the middle of ac load line

• approximately at the collector cut off on both dc& ac load lines

• at the middle of dc Load line

• below cut off region of ac load line