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MCQOPTIONS
This section includes 1362 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1351. |
A 400 W carrier is amplitude modulated with m = 0.75. The total power in AM is |
| A. | 400 W |
| B. | 512 W |
| C. | 588 W |
| D. | 650 W |
| Answer» C. 588 W | |
| 1352. |
If a signal band limited for fm is sampled at a rate less than 2 fm the reconstructed signal will be |
| A. | smaller in amplitude |
| B. | distorted |
| C. | having higher frequencies suppressed |
| D. | none of the above |
| Answer» C. having higher frequencies suppressed | |
| 1353. |
For an ideal 3000 Hz channel, S/N ratio is |
| A. | 3 |
| B. | 1.5 |
| C. | 4 |
| D. | 2 |
| Answer» B. 1.5 | |
| 1354. |
VSB modulation is preferred in TV because |
| A. | it reduces the bandwidth requirement to half |
| B. | it avoids phase distortion at low frequencies |
| C. | it results in better reception |
| D. | none of the above |
| Answer» B. it avoids phase distortion at low frequencies | |
| 1355. |
In standing wave pattern on a transmission line |
| A. | voltage and current nodes coincide |
| B. | voltage and current antinodes coincide |
| C. | voltage nodes and current antinodes as well as current nodes and voltage antinodes coincide |
| D. | both (a) and (b) |
| Answer» D. both (a) and (b) | |
| 1356. |
If sound intensity is 8 W/m2, the dB level of this sound is about |
| A. | 5 dB |
| B. | 50 dB |
| C. | 129 dB |
| D. | 1290 dB |
| Answer» D. 1290 dB | |
| 1357. |
If the target cross-section is changing, the best scanning system for accurate tracking is |
| A. | lobe switching |
| B. | monopulse |
| C. | sequential lobing |
| D. | conical scanning |
| Answer» C. sequential lobing | |
| 1358. |
In VCR the luminance signal is recorded by |
| A. | frequency modulation |
| B. | phase modulation |
| C. | amplitude modulation |
| D. | direct recording |
| Answer» B. phase modulation | |
| 1359. |
24 telephone channels, each band limited to 3.4 kHz are to be time division multiplexed using PCM. If sampling frequency is 10 kHz and number of quantization levels is 128, the required bandwidth of PCM is |
| A. | 1.68 MHz |
| B. | 240 kHz |
| C. | 81.6 kHz |
| D. | 3.072 MHz |
| Answer» B. 240 kHz | |
| 1360. |
The colour subcarrier and sidebands produced by its modulation with the chrominance signals are accommodated in the standard channel width by the process of |
| A. | frequency adjustment |
| B. | frequency interleaving |
| C. | frequency changing |
| D. | frequency amalgamation |
| Answer» C. frequency changing | |
| 1361. |
The rate at which information can be carried through a communication channel depends on |
| A. | carrier frequency |
| B. | bandwidth |
| C. | transmission loss |
| D. | transmitted power |
| Answer» C. transmission loss | |
| 1362. |
A cordless telephone using separate frequencies for transmission in base and portable units is known as |
| A. | duplex arrangement |
| B. | half duplex arrangement |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» B. half duplex arrangement | |