Electronics and Communication Engineering - Radio Receivers

Exercise :: Radio Receivers - Section 1

46. 

In superheterodyne receivers, the local oscillator is used to

A. detect the modulating signal
B. amplify the received modulated carrier
C. shift the frequency of the received modulated carrier to the IF band

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.

47. 

Which of the following is same in AM and FM receivers?

A. Demodulator
B. AGC
C. IF amplifier
D. All of the above

Answer: Option C

Explanation:

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48. 

A notch filter is sometimes used in communication receivers to

A. reduce receiver gain at some specific frequency
B. increase receiver gain at some specific frequency
C. made selectivity more precise
D. spread the bandwidth

Answer: Option A

Explanation:

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49. 

Which one of the following is not a useful quantity for comparing the noise performance of receivers?

A. Noise figure
B. Noise temperature
C. Input noise voltage
D. Equivalent noise resistance

Answer: Option C

Explanation:

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50. 

Which of the following statement about the amplitude limiter is not valid?

A. Leak type bias must be used
B. Output must be tuned
C. The circuit is always biased in class C, by virtue of the leak type bias
D. When the input increases past the threshold of limiting, the gain decreases to keep the output constant

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.

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