# Analog Communication 6

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject:  Analog Communication 6

Part 6: List for questions and answers of Analog Communication

Q1. 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

Q2. 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

Q3. 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

Q4. 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

Q5. In terms of signal frequency (fs) and intermediate frequency (fi), the image frequency is given by

a) fs + fi

b) fs + 2fi

c) 2fs + fi

d) 2( fs + fi)

Q6. 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

Q7. The costas receiver is used for

a) FM signal

b) DSB-SC signal

c) PCM signal

d) DM signal

Q8. 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

Q9. 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

Q10. 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

Q11. The standard value for Intermediate frequency (IF) in AM receivers is

a) 455 KHz

b) 580 KHz

c) 10.7 MHz

d) 50 MHz

Q12. Example of continuous wave analog modulation is

a) PCM

b) DM

c) AM

d) PAM

Q13. Intermediate frequency (IF) should be carefully chosen as

a) High IF results in poor selectivity

b) High IF results in problems in tracking of signals

c) Image frequency rejection becomes poor at low IF

d) All of the above

Q14. Advantages of using an RF amplifier are:

a) Better selectivity

b) Better sensitivity

c) Improved signal to noise ratio

d) All of the above

Q15. Selectivity of a receiver:

a) Changes with incoming signal frequency

b) Is poorer at high frequencies

c) Is the rejection of the adjacent channel at the receiver

d) All of the above

Q16. The factors that determine the sensitivity of super heterodyne receiver are

a) Gain of the IF amplifier

b) Noise figure of the receiver

c) Gain of RF amplifier

d) All of the above

Q17. In Automatic gain control of the AM receiver

a) Gain of the receiver is adjusted

b) The gain adjustment depends upon the strength of the received signal

c) The output provided is a DC voltage

d) All of the above

Q18. Squelch circuit is

a) Suppresses output audio

b) Works when there is insufficient desired input signal

c) Is used to suppress the unwanted channel noise when there is no reception by the receiver

d) All of the above

Q19. Frequency components of an AM wave (m = modulation index) are

a) Carrier frequency (wc ) with amplitude A

b) Upper side band (wc + wm) having amplitude mA/2

c) Lower side band (wc – wm) having amplitude mA/2

d) All of the above

Q20. Examples of low level modulation are

a) Square law diode modulation

b) Switching modulation

c) Frequency discrimination method

d) Both a and b

Part 6: List for questions and answers of Analog Communication