| 1. | If the radiated power of AM transmitter is 10 KW, the power in the carrier for modulation index of 0.6 is nearly ? | |
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8.24kW
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8.47kW
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9.26kW
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9.6kW
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Report Question| 2. | A communication channel is having a bandwidth of 300 Hz. The transmitted power is such that the received signal-to-noise ratio is 102. The maximum data rate that can be transmitted t error- free through the channel is ? | |
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3 Kbps
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30 Kbps
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3 Mbps
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300 Kbps
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| 3. | Use of pre-emphasis ? | |
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For amplify low frequency
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For amplify high frequency
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For amplify both high and low frequency
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For attenuate both high and low frequency
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| 4. | A PCM system uses a uniform Quantizer which has a range- V to +V and is followed by a 7 bit binary encoder. A zero mean signal applied to the quantizer extends over its entire range and has uniform probability density. The ratio of the signal power of the quantization noise power at the output of the quantizer is (Take log102 = 0.3 ) ? | |
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14dB
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28dB
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42dB
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56dB
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| 5. | Two resistors R1 and R2 and (in ohms) at temperatures T1K and T2K respectively, are connected in series. Their equivalent noise temperature is ? | |
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T1+T2
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R1T2+R2T2
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(R1T1+R2T2)/(R1R2)
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(R1T1+R2T2)/(R1+R2)
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| 6. | De-emphasis circuit is used ? | |
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After modulation
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After detection
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Before modulation
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Before detection
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| 7. | Identify the modulation schemes for the shown signal constellation diagrams ? | |
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A-QPSK B-BPSK C-QAM
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A-OPSK B-OQPSK C-MSK
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A-OQPSK B-QAM C-QPSK
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A-OQPSK B-QPSK C-MSK
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| 8. | In communication systems, noise is most likely to effect the signal ? | |
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In the transmitter
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In the information source
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In the channel
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At the destinations
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| 9. | Time gap between two byte in a synchronous transmission is ? | |
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Fixed
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Zero
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Differentiation of data rate
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variable
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| 10. | When signal frequency is 2000 KHz and IF is 455 KHz, the image frequency could be ? | |
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2910 KHz
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1645 KHz
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2455 KHz
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2090 KHz
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