MCQOPTIONS
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MCQOPTIONS
This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Devices and Circuits knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If a matched attenuator with a loss of 3.2 dB is placed between the source and the amplifier s input, what is the operating spot noise figure of the attenuator amplifier cascade if the attenuator s physical temperature is 290 K? |
| A. | 9 db |
| B. | 11.3 db |
| C. | 10.4 db |
| D. | 13.3 db |
| Answer» E. | |
| 2. |
What is the maximum average effective input noise temperature that an amplifier can have if its average standard noise figure is to not exceed 1.7? |
| A. | 203 K |
| B. | 215 K |
| C. | 235 K |
| D. | 255 K |
| Answer» B. 215 K | |
| 3. |
An amplifier when used with a source of average noise temperature 60 K, has an average operating noise figure of 5. What average operating noise figure results when the amplifier is used with an antenna of temperature 30 K? |
| A. | 9.54 db |
| B. | 10.96 db |
| C. | 11.23 db |
| D. | 12.96 db |
| Answer» B. 10.96 db | |
| 4. |
An amplifier when used with a source of average noise temperature 60 K, has an average operating noise figure of 5. If the amplifier is sold to the engineering public, the noise figure that would be quoted in a catalog is? |
| A. | 0.46 |
| B. | 0.94 |
| C. | 1.83 |
| D. | 2.93 |
| Answer» D. 2.93 | |
| 5. |
An amplifier when used with a source of average noise temperature 60 K, has an average operating noise figure of 5. What is the value of Te? |
| A. | 70 K |
| B. | 110 K |
| C. | 149 K |
| D. | 240 K |
| Answer» E. | |
| 6. |
A system has three stage cascaded amplifier each stage having a power gain of 10 dB and noise figure of 6 dB. the overall noise figure is |
| A. | 1.38 |
| B. | 6.8 |
| C. | 4.33 |
| D. | 10.43 |
| Answer» D. 10.43 | |
| 7. |
A mixer stage has a noise figure of 20 dB. This mixer stage is preceded by an amplifier which has a noise figure of 9 dB and an available power gain of 15 dB. The overall noise figure referred to the input is |
| A. | 11.07 |
| B. | 18.23 |
| C. | 56.43 |
| D. | 97.38 |
| Answer» B. 18.23 | |
| 8. |
In a receiver the input signal is 100 V, while the internal noise at the input is 10 V. With amplification the output signal is 2 V, while the output noise is 0.4 V. The noise figure of receiver is |
| A. | 2 |
| B. | 0.5 |
| C. | 0.2 |
| D. | None of the mentioned |
| Answer» B. 0.5 | |