Broadband Communication Systems 4

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Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Broadband Communication Systems 4

Part 4: List for questions and answers of Broadband Communication Systems


Q1. For an ideal 3000 hz channel, s/n ratio is

a) 3

b) 1.5

c) 4

d) 2


Q2. Which of the following types of noise assumes greater importance at high frequencies?

a) transit time noise

b) Shot noise

c) Impulse noise

d) Random noise


Q3. In transistor radio receivers the number of if amplifier stages are

a) 1

b) 2

c) 4

d) 6


Q4. To relay outdoor remotely located live programs, tv transmitter use

a) microwave links

b) Coaxial cable link

c) Open wire link

d) Either (b) or (c)


Q5. If each short element of signal occupies 20 ms, the speed is

a) 20 bauds

b) 50 bauds

c) 1/50 bauds

d) 0.05 bauds


Q6. It is found that in a telephone system 60 subscribers initiate calls during a 30 minute interval and the total duration of all the calls is 100 minutes. The load is

a) 2

b) 3 erlang

c) 3.333 erlang

d) 0.333 erlang 


Q7. If transmission bandwidth is doubled in fm, snr is

a) Doubled

b) Raised four times

c) decreased four times

d) Halved


Q8. Directivity means

a) maximum directive gain

b) Zero directive gain

c) Minimum directive gain

d) None of the above


Q9. If the oscillator output is modulated by audio frequencies upto 10 khz, the frequency range occupied by the side bands will be

a) 711.9 khz to 712.1 khz

b) 702 khz to 722 khz

c) 692 khz to 732 khz

d) 71.2 khz to 71.20 khz


Q10. The power to the portable unit of a cordless telephone is provided by

a) Pencil cells

b) Dry cells

c) rechargeable cells

d) Ac mains


Q11. In a am wave the carrier and one of the side bands is suppressed. If m = 0.5, the percentage saving in power is

a) 50%

b) 83.3%

c) 94.4%

d) 100%


Q12. Computer communication networks have

a) Star configuration

b) Tree configuration

c) Loop/mesh configuration

d) all of the above 


Q13. Assertion (a): a balun is an rf impedance matching transformer. Reason (r): sometimes a booster amplifier is used with a tv set.

a) Both a and r are correct and r is correct explanation of a

b) both a and r are correct but r is not correct explanation of a

c) A is correct but r is wrong

d) A is wrong but r is correct


Q14. In an fm system, when the af is 500 hz and the af voltage is 2.4 v, the deviation is 4.8 khz. If the af voltage is now increased to 7.2 v, the new deviation will be

a) 4.8 khz

b) 9.6 khz

c) 14.4 khz

d) 28.8 khz


Q15. The maximum range of a transmitter depends on

a) Its frequency

b) Its power

c) both its frequency and power

d) None of the above


Q16. In a two stage cascade amplifier, each stage has a gain of 10 db and noise figure of 10 db. The overall noise factor is

a) 10

b) 1.09

c) 1

d) 10.9


Q17. Fields are said to be circularly polarised if their magnitudes are

a) Equal and they are in phase

b) equal but they differ in phase by ± 90°.

c) Unequal and differ in phase by ± 90°.

d) Unequal but are in phase


Q18. Three analog signals, having bandwidths 1200 hz, 600 hz, 600 hz are sampled at their nyquist rates, encoded with 12 bit words, and time division multiplexed. The bit rate for the multiplexed signal is

a) 115.2 kbps

b) 28.8 kbps

c) 57.6 kbps

d) 38.4 kbps 


Q19. In a cd player the speed of cd is

a) Constant at 500 rpm

b) Constant at 200 rpm

c) varies from 200 to 500 rpm

d) None of the above


Q20. In the output of a dm speech encoder, the consecutive pulses are of opposite polarity during time interval t1 is less than t is less than t2. This indicates that during this interval

a) the input to the modulator is essentially constant

b) The modulator is going through slope overload

c) The accumulator is in saturation

d) The speech signal is being sampled at the nyquist rate 


Part 4: List for questions and answers of Broadband Communication Systems


Q1. Answer: a


Q2. Answer: a


Q3. Answer: b


Q4. Answer: a


Q5. Answer: b


Q6. Answer: c


Q7. Answer: c


Q8. Answer: a


Q9. Answer: b


Q10. Answer: c


Q11. Answer: c


Q12. Answer: d


Q13. Answer: b


Q14. Answer: c


Q15. Answer: c


Q16. Answer: d


Q17. Answer: b


Q18. Answer: c


Q19. Answer: c


Q20. Answer: a