MCQOPTIONS
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MCQOPTIONS
This section includes 26 Mcqs, each offering curated multiple-choice questions to sharpen your Optical Communication knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Determine CW operating lifetime for LED with βrt = -0.58 and degradation rate βr = 7.86*10-11 h-1. |
| A. | 32.12 |
| B. | 42 |
| C. | 22.72 |
| D. | 23.223 |
| Answer» D. 23.223 | |
| 2. |
Determine degradation rate βrif constant junction temperature is 17 degree celsius. |
| A. | 7.79*10-11 |
| B. | 7.91*10-11 |
| C. | 6.86*10-11 |
| D. | 5.86*10-11 |
| Answer» B. 7.91*10-11 | |
| 3. |
The 3 dB electrical bandwidth B is 42 MHz. Determine 3dB optical bandwidth Bopt. |
| A. | 45.18 |
| B. | 59.39 |
| C. | 78.17 |
| D. | 94.14 |
| Answer» C. 78.17 | |
| 4. |
Determine the 3 dB electrical bandwidth at 3 dB optical bandwidth Bopt of 56.2 MHz. |
| A. | 50.14 |
| B. | 28.1 |
| C. | 47.6 |
| D. | 61.96 |
| Answer» C. 47.6 | |
| 5. |
The optical power at 20 MHz is 246.2 μW. Determine dc drive current applied to device with carrier recombination lifetime for LED of 6ns. |
| A. | 3.48*10-4 |
| B. | 6.42*10-9 |
| C. | 1.48*10-3 |
| D. | 9.48*10-12 |
| Answer» B. 6.42*10-9 | |
| 6. |
When a constant d.c. drive current is applied to device, the optical o/p power is 320 μm. Determine optical o/p power when device is modulated at frequency 30 MHz with minority carrier recombination lifetime of LED i.e. 5ns. |
| A. | 4.49*10-12 |
| B. | 6.84*10-9 |
| C. | 1.29*10-6 |
| D. | 2.29*10-4 |
| Answer» E. | |
| 7. |
The optical bandwidth is _____________ the electrical bandwidth. |
| A. | Smaller |
| B. | Greater |
| C. | Same as |
| D. | Zero with respect to |
| Answer» C. Same as | |
| 8. |
The optical 3 dB point occurs when currents ratio is equal to _____________ |
| A. | \(\frac{8}{3}\) |
| B. | \(\frac{2}{2}\) |
| C. | \(\frac{1}{2}\) |
| D. | \(\frac{3}{4}\) |
| Answer» D. \(\frac{3}{4}\) | |
| 9. |
The active layer composition must be adjusted if a particular center wavelength is desired. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 10. |
The internal quantum efficiency of LEDs decreasing _______________ with ________________ temperature. |
| A. | Exponentially, decreasing |
| B. | Exponentially, increasing |
| C. | Linearly, increasing |
| D. | Linearly, decreasing |
| Answer» C. Linearly, increasing | |
| 11. |
Linearizing circuit techniques are used for LEDs. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 12. |
THE_OPTICAL_BANDWIDTH_IS_______________THE_ELECTRICAL_BANDWIDTH.?$ |
| A. | Smaller |
| B. | Greater |
| C. | Same as |
| D. | Zero with respect to |
| Answer» C. Same as | |
| 13. |
The optical power at 20 MHz is 246.2 μW. Determine dc drive current applied to device with carrier recombination lifetime for LED of 6ns.$# |
| A. | 3.48*10<sup>-4 </sup> |
| B. | 6.42*10<sup>-9</sup> |
| C. | 1.48*10<sup>-3</sup> |
| D. | 9.48*10<sup>-12</sup> |
| Answer» B. 6.42*10<sup>-9</sup> | |
| 14. |
When_a_constant_d.c._drive_current_is_applied_to_device,_the_optical_o/p_power_is_320_μm._Determine_optical_o/p_power_when_device_is_modulated_at_frequency_30_MHz_with_minority_carrier_recombination_lifetime_of_LED_i.e._5ns.$# |
| A. | 4.49*10<sup>-12</sup> |
| B. | 6.84*10<sup>-9</sup> |
| C. | 1.29*10<sup>-6</sup> |
| D. | 2.29*10<sup>-4</sup> |
| Answer» E. | |
| 15. |
Determine CW operating lifetime for LED with βrt = -0.58 and degradation rate βr= 7.86*10-11 h-1.$ |
| A. | 32.12 |
| B. | 42 |
| C. | 22.72 |
| D. | 23.223 |
| Answer» D. 23.223 | |
| 16. |
Determine degradation rate βrif constant junction temperature is 17 degree celsius.$ |
| A. | 7.79*10<sup>-11</sup> |
| B. | 7.91*10<sup>-11</sup> |
| C. | 6.86*10<sup>-11</sup> |
| D. | 5.86*10<sup>-11</sup> |
| Answer» B. 7.91*10<sup>-11</sup> | |
| 17. |
The 3 dB electrical bandwidth B is 42 MHz. Determine 3dB optical bandwidth Bopt: |
| A. | 45.18 |
| B. | 59.39 |
| C. | 78.17 |
| D. | 94.14 |
| Answer» C. 78.17 | |
| 18. |
Determine_the_3_dB_electrical_bandwidth_at_3_dB_optical_bandwidth_Bopt_of_56.2_MHz. |
| A. | 50.14 |
| B. | 28.1 |
| C. | 47.6 |
| D. | 61.96 |
| Answer» C. 47.6 | |
| 19. |
The optical 3 dB point occurs when currents ratio is equal t? |
| A. | ‚Öù |
| B. | ‚Öî |
| C. | ¬Ω |
| D. | ¾ |
| Answer» D. ¬¨¬®‚àö¬∂ | |
| 20. |
In optical fiber communication, the electrical signal dropping to half its constant value due to modulated portion of optical signal corresponds to _______ |
| A. | 6 dB |
| B. | 3 dB |
| C. | 4 dB |
| D. | 5 db |
| Answer» C. 4 dB | |
| 21. |
The active layer composition must be adjusted if a particular center wavelength is desired.State whether the given statement is true or false. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 22. |
For particular materials with smaller bandgap energies operating in _____________ wavelength, the linewidth tends to ______________ |
| A. | 2.1 to 2.75 μm, increase |
| B. | 1.1 to 1.7 μm, increase |
| C. | 2.1 to 3.6 μm, decrease |
| D. | 3.5 to 6 μm, decrease |
| Answer» C. 2.1 to 3.6 ‚âà√≠¬¨‚à´m, decrease | |
| 23. |
To utilize _____________________ of SLDs at elevated temperatures, the use of thermoelectric coolers is important. |
| A. | Low-internal efficiency |
| B. | High-internal efficiency |
| C. | High-power potential |
| D. | Low-power potential |
| Answer» D. Low-power potential | |
| 24. |
The internal quantum efficiency of LEDs decreasing _______________ with ________________ temperature. |
| A. | Exponentially, decreasing |
| B. | Exponentially, increasing |
| C. | Linearly, increasing |
| D. | Linearly, decreasing |
| Answer» C. Linearly, increasing | |
| 25. |
Linearizing circuit techniques are used for LEDs. State whether the given statement is true or false. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 26. |
Intrinsically _________________ are a very linear device. |
| A. | Injection lasers |
| B. | DH lasers |
| C. | Gain-guided |
| D. | LEDs |
| Answer» E. | |