Communication Systems - Section 1 (6)
Communication Systems - Section 1
| 41. | Energy content of atmospheric noise |
|||||||
Answer: Option B Explanation: Atmospheric noise decreases as frequency is increased. |
| 42. | The number of noise sources in a BJT are |
|||||||
Answer: Option A Explanation: Shot noise, partition noise and thermal noise. |
| 43. | In colour TV receiver, varactor diode is used for |
|||||||
Answer: Option C Explanation: In varactor diode the applied reverse bias controls the width and therefore capacitance of depletion layer. This capacitance is used for tuning. |
| 44. | In FM signal with a modulation index mf is passed through a frequency tripler. The wave in the output of the tripler will have a modulation index of |
|||||||
|
| 45. | The colour subcarrier and sidebands produced by its modulation with the chrominance signals are accommodated in the standard channel width by the process of |
|||||||
Answer: Option B Explanation: In frequency interleaving the space between bundles is used for colour signal. |
| 46. | A woofer should be fed from the input through a |
|||||||
Answer: Option A Explanation: Woofer is a low frequency loud speaker covering the range 16 Hz to 500 Hz. |
| 47. | VSB modulation is preferred in TV because |
|||||||
Answer: Option A Explanation: VSB (vestigial side band) transmission transmits one side band fully and the other side band partially thus, reducing the bandwidth requirement. |
| 48. | A modem is classified as low speed if data rate handled is |
|||||||
Answer: Option D Explanation: When data rate in bits per second is upto 600, modem is low speed. |