Analog Communication Test Questions - Set 5

1)   Example of continuous wave analog modulation is

a. PCM
b. DM
c. AM
d. PAM
Answer  Explanation 

ANSWER: AM

Explanation:
No explanation is available for this question!


2)   The standard value for Intermediate frequency (IF) in AM receivers is

a. 455 KHz
b. 580 KHz
c. 10.7 MHz
d. 50 MHz
Answer  Explanation 

ANSWER: 455 KHz

Explanation:
No explanation is available for this question!


3)   The functions of radio receiver are

a. Receive the Incoming modulated carrier by antenna
b. Select the wanted signal and reject the unwanted signals and noise
c. Detection and amplification of the information signal from the carrier
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!


4)   Function of frequency mixer in super heterodyne receiver is

a. Amplification
b. Filtering
c. Multiplication of incoming signal and the locally generated carrier
d. None of the above
Answer  Explanation 

ANSWER: Multiplication of incoming signal and the locally generated carrier

Explanation:
No explanation is available for this question!


5)   The advantages of using an RF amplifier are

a. Better sensitivity
b. Improved signal to noise ratio
c. Better selectivity
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!


6)   The costas receiver is used for

a. FM signal
b. DSB-SC signal
c. PCM signal
d. DM signal
Answer  Explanation 

ANSWER: DSB-SC signal

Explanation:
No explanation is available for this question!


7)   Cross talk is -

a. The disturbance caused in the nearby channel or circuit due to transmitted signal
b. Adjacent frequency rejection
c. Generation of closely lying side bands
d. None of the above
Answer  Explanation 

ANSWER: The disturbance caused in the nearby channel or circuit due to transmitted signal

Explanation:
No explanation is available for this question!


8)   In Frequency Modulation -

a. Amplitude of the carrier remains same
b. Frequency of the carrier varies in accordance with the modulating signal
c. The number of side bands are infinite
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!


9)   Frequency deviation in FM is

a. Change in carrier frequency to the frequency above and below the centre frequency
b. Formation of side bands
c. The variation of the instantaneous carrier frequency in proportion to the modulating signal
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!


10)   Carrier swing is defined as

a. The total variation in frequency from the lowest to the highest point
b. Frequency deviation above or below the carrier frequency
c. Width of the side band
d. None of the above
Answer  Explanation 

ANSWER: The total variation in frequency from the lowest to the highest point

Explanation:
No explanation is available for this question!


11)   The amount of frequency deviation in FM signal depends on

a. Amplitude of the modulating signal
b. Carrier frequency
c. Modulating frequency
d. Transmitter amplifier
Answer  Explanation 

ANSWER: Amplitude of the modulating signal

Explanation:
No explanation is available for this question!


12)   Drawbacks of using direct method for generation of FM signal are

a. Does not give high stability to FM signal frequency
b. Distorted FM signal is generated due to harmonics of modulating signal
c. Cannot be used for high power FM generation
d. Both a and b
Answer  Explanation 

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


13)   Advantage of using direct method for generation of FM signal is

a. It gives high stability to FM signal frequency
b. Distortion free FM signal is generated
c. High power FM generation is possible
d. None of the above
Answer  Explanation 

ANSWER: High power FM generation is possible

Explanation:
No explanation is available for this question!


14)   What are the disadvantages of using balanced slope detector for demodulation of FM signal?

a. The detector operates only for small deviation in frequency
b. Low pass filter of the detector produces distortion in the detection
c. Both a and b
d. None of the above
Answer  Explanation 

ANSWER: Both a and b

Explanation:
No explanation is available for this question!


15)   Drawbacks of Tuned Radio Receiver are

a. Oscillate at higher frequencies
b. Selectivity is poor
c. Bandwidth of the TRF receiver varies with incoming frequency
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!


16)   Sensitivity is defined as

a. Ability of receiver to amplify weak signals
b. Ability to reject unwanted signals
c. Ability to convert incoming signal into Image Frequency
d. Ability to reject noise
Answer  Explanation 

ANSWER: Ability of receiver to amplify weak signals

Explanation:
No explanation is available for this question!


17)   In radio receivers, varactor diodes are used for

a. Tuning
b. Demodulation
c. Mixing
d. None of the above
Answer  Explanation 

ANSWER: Tuning

Explanation:
No explanation is available for this question!


18)   The standard value for Intermediate frequency (IF) in double conversion FM receivers is

a. 455 KHz
b. 580 KHz
c. 10.7 MHz
d. 50 MHz
Answer  Explanation 

ANSWER: 10.7 MHz

Explanation:
No explanation is available for this question!


19)   Amplitude limiter in FM receivers are used to

a. Remove amplitude variations due to noise
b. Filteration
c. Demodulation
d. Amplification
Answer  Explanation 

ANSWER: Remove amplitude variations due to noise

Explanation:
No explanation is available for this question!


20)   Pre emphasis is done

a. For boosting of modulating signal voltage
b. For modulating signals at higher frequencies
c. In FM before modulation
d. All of the above
Answer  Explanation 

ANSWER: All of the above

Explanation:
No explanation is available for this question!