155. A sine wave is passed through an amplifier which severely limits it symmetrically. It then passes to a second amplifier which is narrow band and tuned to the frequency of the original sine wave. What will be the output waveform from this second amplifier?
A. A square wave of the same frequency as that of original sine wave
B. A square wave of double the frequency of that of original sine wave
C. A sine wave of constant ampliude at the frequency of the original sine wave
D. A sine wave of constant amplitude at double the frequency of the original sine wave.

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156. For an amplifier, the coupling method which gives the highest gain is
A. impedance coupling
B. transformer coupling
C. capacitance coupling
D. resistance coupling

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157. For high frequency response of a transistor amplifier, suitable model to use is
A. Kelvin network
B. Lattice network
C. Hybrid it
D. T-network

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158. The bandwidth of a differential amplifier is comparable to that of a
A. Cascade amplifier
B. Darlington amplifier Double stage CE amplifier
C. Single stage CE amplifier
D. none of the above

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159. The third harmonic of 300 Hz is
A. 100 Hz
B.3001-Iz
C. 900 Hz
D.2700 Hz

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160. The main function of transformer used In the output of a power amplifier is
A. to step-up the voltage
B. to increase the voltage gain
C. to match the load impedance with dynamic output resistance of the transistor
D. to safeguard the transistor against overheating.

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161.  An RF amplifier has a frequency response curve with the following characteristics: Down 1 dB at 1.4 and 1.5 MHz Down 3 dB at 1.3 and 1.6 MHz Down 60 dB at 0.9 and 2.0 MHz What will be the standard bandwidth?
A. 0.03 Mliz
B. 0.3 MHz
C. 30 MHz
D. 130 MHz

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