148. A cascade amplifier will have higher cut-off frequency
A. equal to that of single stage amplifier
B. less than that of single stage amplifier
C. more than that of single stage amplifier.
149. A push pull amplifiers balances out
A. odd harmonics
B. even harrnoics
C. both odd' as well as even harmonics .
D. neither odd nor even harmonics
150. Two I.F. amplifier stages tuned to a frequency of 456 kHz are cascade. What should be the quality factors of the tuned circuits if the bandwidth is to be 10 kHz and single tuned circuit is used?
151. Which of the following circuit has the greatest bandwidth?
A. fr = 1 MHz ; Q = 10
B. = 4551(Hz ; Q = 100
C. f= 1 MHz ; Q = 100
D. fr= 50 MHz; Q = 50
152. A push pull class B amplifier uses two AC 126 transistors, transformer coupled to a speaker of 3 ohms. The turns ratio is 20 and the supply voltage is 9 V. Assumig transformer to be ideal, the maximum collector current will be
A. 1 mA
B. 5 mA
C. 15 tnA
D. 30 tnA
153. The power output in above question will be
A. 15 mW
B. 30 mW
C. 45 mW
D. 135 mW
154. The second harmonic distortion in an amplifier is reduced from 5% to 1% due to negative feedback. If the amplifier gain is 1000, the feedback ratio should be
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