MCQOPTIONS
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MCQOPTIONS
This section includes 19 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Mechanic knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In simplex channel, the flow of data is |
| A. | In both directions, but one at a time |
| B. | Always in both direction |
| C. | Always in one direction |
| D. | None of the above |
| Answer» D. None of the above | |
| 2. |
________ is a low earth orbit satellite constellation for satellite phone and low-speed data communications. |
| A. | Globalstar |
| B. | Meridian |
| C. | Bridgeway |
| D. | Leosat |
| Answer» B. Meridian | |
| 3. |
Optical fibre communication works on the principle of |
| A. | Interference |
| B. | Total Internal Reflection. |
| C. | Diffraction. |
| D. | Photo Electric Effect |
| Answer» C. Diffraction. | |
| 4. |
On which element of the Yagi-Uda Antenna is signal power applied/received? |
| A. | Director |
| B. | Reflector |
| C. | Driven element |
| D. | Second director |
| Answer» D. Second director | |
| 5. |
Following are the wavelength bands used in optical communication systems.(a) Long (L) Band(b) Conventional band (C band)(c) Extended band (E band)(d) Original band (O-band)Arrange them in increasing order of wavelengths. The correct sequence is: |
| A. | (d), (c), (b), (a) |
| B. | (c), (b), (a), (d) |
| C. | (b), (c), (a), (d) |
| D. | (a), (b), (c), (d) |
| Answer» B. (c), (b), (a), (d) | |
| 6. |
For a satellite transponder with a receiver antenna gain of 12 dB, an LNA gain of 10 dB, and equivalent noise temperature of 26 dBK-1, the G/Te is |
| A. | 4 dBK-1 |
| B. | -4 dBK-1 |
| C. | 26 dBK-1 |
| D. | -26 dBK-1 |
| Answer» C. 26 dBK-1 | |
| 7. |
IF values of AM receivers lie between: |
| A. | 50 kHz to 250 kHz |
| B. | 5 kHz to 25 kHz |
| C. | 50 kHz to 25 kHz |
| D. | 430 kHz to 25 MHz |
| Answer» E. | |
| 8. |
Consider the following statements about the maximum usable frequency (MUF) for radio communicationbetween two specified points using an ionospheric layer:1. MUF is equal to critical frequency2. MUF is more than the critical frequency3. MUF depends upon the height of the ionospheric layer4. MUF depends upon the distance between the two pointsWhich of these statements are correct? |
| A. | 1, 2, 3 and 4 |
| B. | 2 and 3 only |
| C. | 3 and 4 only |
| D. | 2 and 4 only |
| Answer» E. | |
| 9. |
Name the ionization layer that exists during day time and usually vanishes at night due to highest recombination rate |
| A. | Appleton region |
| B. | D Region |
| C. | Normal E region |
| D. | Sporadic E region |
| Answer» C. Normal E region | |
| 10. |
In microwave ovens, the commonly used radio wave frequency is roughly________ |
| A. | 2,500 megahertz |
| B. | 8000 kilohertz |
| C. | 1000 megahertz |
| D. | None of these |
| Answer» B. 8000 kilohertz | |
| 11. |
A capacitor and coil in parallel is called |
| A. | Tuned Circuit |
| B. | Timing Circuit |
| C. | Delay Circuit |
| D. | Schmitt Circuit |
| Answer» B. Timing Circuit | |
| 12. |
An AM receiver is tuned to 855 kHz. If IF is 455 kHz, what is the local oscillator frequency? |
| A. | 400 kHz |
| B. | 1310 kHz |
| C. | 1500 kHz |
| D. | 1520 kHz |
| Answer» C. 1500 kHz | |
| 13. |
Name the scientific principle behind the working of optical fibres. |
| A. | Total external refraction of light |
| B. | Total internal refraction of light |
| C. | Total internal reflection of light |
| D. | Total external reflection of light |
| Answer» D. Total external reflection of light | |
| 14. |
PCM stands for ________ |
| A. | Pulse carrier modulation |
| B. | Primary code Modulation |
| C. | Pulse code Modulation |
| D. | Primary channel modulation |
| Answer» D. Primary channel modulation | |
| 15. |
Line-of-sight propogation is done by |
| A. | MEO Satellites |
| B. | GEO Satellites |
| C. | LEO Satellites |
| D. | GEO Stationary Satellites |
| Answer» E. | |
| 16. |
Laser is a |
| A. | Light Source |
| B. | Light Detector |
| C. | Both Light Source & Light Detector |
| D. | None of these |
| Answer» B. Light Detector | |
| 17. |
Parity bit check is used to |
| A. | Detect 1-bit error |
| B. | Correct 1-bit error |
| C. | Detect and correct 1-bit error |
| D. | Correct 2-bit error |
| Answer» B. Correct 1-bit error | |
| 18. |
If an Antenna draws 12 A current and radiates 4 kW, then what will be its radiation resistance |
| A. | 22.22 Ω |
| B. | 27.77 Ω |
| C. | 33.33 Ω |
| D. | 39.77 Ω |
| Answer» C. 33.33 Ω | |
| 19. |
In industrial communication, DTE stands for: |
| A. | Data Termination Equipment |
| B. | Digital Transmission Error |
| C. | Data Transmission Equipment |
| D. | Data Transmission Error |
| Answer» B. Digital Transmission Error | |