MCQOPTIONS
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MCQOPTIONS
This section includes 25 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
*/*_In a broadcast superheterodyne receiver, the? |
| A. | Local oscillator operates below the signal frequency |
| B. | Mixer input must be tuned to the signal frequency |
| C. | Local oscillator frequency is normally double the IF |
| D. | RF amplifier normally works at 455 kHz above the carrier frequency |
| Answer» C. Local oscillator frequency is normally double the IF | |
| 2. |
*/*_In a radio receiver with simple AGC? |
| A. | An increase in signal strength produces more AGC |
| B. | The audio stage gain is normally controlled by the AGC |
| C. | The faster the AGC time constant the more accurate the output |
| D. | The highest AGC voltage is produced |
| Answer» B. The audio stage gain is normally controlled by the AGC | |
| 3. |
*/*_When a receiver has good blocking performance, this means that? |
| A. | It does not suffer from double-spotting |
| B. | Its image frequency rejection is poor |
| C. | It is unaffected by AGC derived from nearby transmissions |
| D. | Its detector suffers from burnout |
| Answer» C. It is unaffected by AGC derived from nearby transmissions | |
| 4. |
*/*_A receiver has poor IF selectivity. It will therefore also have poor? |
| A. | Blocking |
| B. | Double-spotting |
| C. | Diversion reception |
| D. | Sensitivity |
| Answer» B. Double-spotting | |
| 5. |
*/*_Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false:? |
| A. | Much easier alignment |
| B. | Better linearity |
| C. | Greater limiting |
| D. | Fewer tuned circuits |
| Answer» D. Fewer tuned circuits | |
| 6. |
_ The image frequency of a superheterodyne receiver$? |
| A. | Is created within the receiver itself |
| B. | Is due to insufficient adjacent channel rejection |
| C. | Is not rejected be the IF tuned circuits |
| D. | Is independent of the frequency to which the receiver is tuned |
| Answer» D. Is independent of the frequency to which the receiver is tuned | |
| 7. |
_ Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that$? |
| A. | The receiver cannot use a phase comparator for AFC |
| B. | Adjacent-channel rejection is more difficult |
| C. | Production of AGC is a rather complicated process |
| D. | The transmission is not compatible with A3E |
| Answer» C. Production of AGC is a rather complicated process | |
| 8. |
_ The typical squelch circuit cuts off$? |
| A. | an audio amplifier when the carrier is absent |
| B. | RF interference when the signal is weak |
| C. | An IF amplifier when the AGC is maximum |
| D. | An IF amplifier when the AGC is minimum |
| Answer» B. RF interference when the signal is weak | |
| 9. |
_ Show which of the following statements about the amplitude limiter is untrue:$? |
| A. | The circuit is always biased in class C, by virtue of the leak-type bias. |
| B. | When the input increases past the threshold of the limiting, the gain decreases to keep the output constant. |
| C. | The output must be tuned |
| D. | Leak-type bias must be used |
| Answer» B. When the input increases past the threshold of the limiting, the gain decreases to keep the output constant. | |
| 10. |
_ One of the following cannot be used to demodulate SSB:$? |
| A. | Product detector |
| B. | Diode Balance modulator |
| C. | Bipolar transistor balanced modulator |
| D. | Complete phase-shift generator |
| Answer» D. Complete phase-shift generator | |
| 11. |
_The frequency generated by each decade in a direct frequency synthesizer is much higher than the frequency shown; this is done to$? |
| A. | Reduce the spurious frequency problem |
| B. | Increase the frequency stability of the synthesizer |
| C. | Reduce the number of decades |
| D. | Reduce the number of crystals required |
| Answer» B. Increase the frequency stability of the synthesizer | |
| 12. |
_Three-point tracking is achieved with$? |
| A. | Variable selectivity |
| B. | The padder capacitor |
| C. | Double spotting |
| D. | Double conversion |
| Answer» C. Double spotting | |
| 13. |
_Indicate the false statement. The superheterodyne receiver replaced the TRF receiver because the latter suffered from$? |
| A. | Gain variation over the frequency coverage range |
| B. | Insufficient gain and sensitivity |
| C. | Inadequate selectivity at high frequencies |
| D. | Instability |
| Answer» C. Inadequate selectivity at high frequencies | |
| 14. |
_The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency$? |
| A. | To help the image frequency rejection |
| B. | To permit easier tracking |
| C. | Because otherwise an intermediate frequency could not be produced |
| D. | To allow adequate frequency coverage without switching |
| Answer» E. | |
| 15. |
_If the intermediate frequency is very high (indicate false statement)$? |
| A. | Image frequency rejection is very good |
| B. | The local oscillator need not be extremely stable |
| C. | The selectivity will be poor |
| D. | Tracking will be improved |
| Answer» E. | |
| 16. |
One of the main functions of the RF amplifier in a superheterodyne receiver is to? |
| A. | Provide improved tracking |
| B. | Permit better adjacent-channel rejection |
| C. | Increase the tuning range of the receiver |
| D. | Improve the rejection of the image frequency |
| Answer» E. | |
| 17. |
In a ratio detector? |
| A. | the linearity is worse than in phase discriminator |
| B. | stabilization against signal strength variations is provided |
| C. | the output is twice that obtainable from a similar phase discriminator |
| D. | the circuit is the same as in a discriminator, except that the diodes are reversed |
| Answer» B. stabilization against signal strength variations is provided | |
| 18. |
If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of? |
| A. | Improving the effectiveness of the AGC |
| B. | Reducing the effect of negative-peak clipping |
| C. | Reducing the effect of noise at low modulation depths |
| D. | Improving the selectivity of the receiver |
| Answer» C. Reducing the effect of noise at low modulation depths | |
| 19. |
A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is? |
| A. | 750 kHz |
| B. | 900 kHz |
| C. | 1650 kHz |
| D. | 2100 kHz |
| Answer» E. | |
| 20. |
Indicate which of the following circuits could not demodulate SSB: |
| A. | Balance modulator |
| B. | Product modulator |
| C. | BFO |
| D. | Phase discriminator |
| Answer» E. | |
| 21. |
Indicate the false statement in connection with communications receivers. |
| A. | The noise limiter cuts off the receiver’s output during a noise pulse. |
| B. | A product demodulator could be used for the reception of Morse code. |
| C. | Double conversion is used to improve image rejection |
| D. | Variable sensitivity is used to eliminate selective fading |
| Answer» E. | |
| 22. |
An AM receiver uses a diode detector for demodulation. This enables it satisfactorily to receive |
| A. | Single-sideband, suppressed-carrier |
| B. | Single-sideband, reduced-carrier |
| C. | ISB |
| D. | Single-sideband, full-carrier |
| Answer» E. | |
| 23. |
To prevent overloading of the IF amplifier in a receiver, one should use |
| A. | Squelch |
| B. | Variable sensitivity |
| C. | Variable selectivity |
| D. | Double conversion |
| Answer» C. Variable selectivity | |
| 24. |
The controlled oscillator synthesizer is sometimes preferred over the direct one because |
| A. | It is a simpler piece of equipment |
| B. | Its frequency stability is better |
| C. | It does not require crystal oscillator |
| D. | It is relatively free of spurious frequency |
| Answer» E. | |
| 25. |
A low ratio of the ac to the dc load impedance of a diode detector results in |
| A. | Diagonal clipping |
| B. | Poor AGC operation |
| C. | Negative-peak clipping |
| D. | Poor AF response |
| Answer» D. Poor AF response | |