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ECE Objective Questions { BJT Amplifiers and Transistor }



99. Class AB operation is often used in power (large signal) amplifiers in order to,
A. get maximum efficiency
B. remove even harmonics
C. overcome cross-over distortion
D. reduce collector dissipation

100. The main use of a class-C amplifier is
A. as an RF amplifier
B. as stereo amplifier
C. in communication soud equipment
D. as distortion generator

101. If a class C powr amplifier has an input signal with frequency of 200 kHz and the width of collector current pulses of 0.1 ItS, then the duty cycle of the amplifier will be
A.1%
B.2%
C.10%
D.20%

102.  The primary cause of linear distortion in amplifiers is
A. change of gain with frequency
B. unequal phase shift in component frequencies
C. reactance associated with the circuit and active amplifying element
D. inherent limitations of the active device

103. An amplifier is said to suffer from distortion when its output is
A. low
B. different from its input
C. noisy
D. larger than its input

104. While discussing amplifier performance, noise is defined as any kind of unwanted signal in the output which is
A. unrelated to the input signal
B. derived from the input signal not generated by the amplifier
C. due to associated circuitry
D.

105. An ideal amplifier has
A. noise figure of less than 1 dB
B. noise factor of unity
C. output SN more than input S/N
D. noise figure of more than 0 dB

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