MCQOPTIONS
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MCQOPTIONS
This section includes 16 Mcqs, each offering curated multiple-choice questions to sharpen your Microwave Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
When either a voltage or current is applied to the terminals of bulk solid state compound GaAs, a differential ______ is developed in that bulk device. |
| A. | negative resistance |
| B. | positive resistance |
| C. | negative voltage |
| D. | none of the mentioned |
| Answer» B. positive resistance | |
| 2. |
THE_NUMBER_OF_MODES_OF_OPERATION_FOR_N_TYPE_GAAS_IS:?$ |
| A. | two |
| B. | three |
| C. | four |
| D. | five |
| Answer» D. five | |
| 3. |
The modes of operation of a Gunn diode are illustrated in a plot of voltage applied to the Gunn diode v/s frequency of operation of Gunn diode.$ |
| A. | true |
| B. | false |
| Answer» C. | |
| 4. |
The_free_electron_concentration_in_N-type_GaAs_is_controlled_by:$ |
| A. | effective doping |
| B. | bias voltage |
| C. | drive current |
| D. | none of the mentioned |
| Answer» B. bias voltage | |
| 5. |
In a Gunn diode oscillator, the electron drift velocity was found to be 107 cm/second and the effective length is 20 microns, then the intrinsic frequency is: |
| A. | 5 GHz |
| B. | 6 GHz |
| C. | 4 GHz |
| D. | 2 GHz |
| Answer» B. 6 GHz | |
| 6. |
In Gunn diode oscillator, the Gunn diode is inserted into a waveguide cavity formed by a short circuit termination at one end |
| A. | true |
| B. | false |
| Answer» B. false | |
| 7. |
The frequency of oscillation in Gunn diode is given by: |
| A. | v<sub>dom</sub>/ L<sub>eff</sub> |
| B. | L<sub>eff</sub>/ V<sub>dom</sub> |
| C. | L<sub>eff</sub>/ WV<sub>dom</sub> |
| D. | none of the mentioned |
| Answer» B. L<sub>eff</sub>/ V<sub>dom</sub> | |
| 8. |
The_mode_of_operation_in_which_the_Gunn_diode_is_not_stable_is: |
| A. | Gunn oscillation mode |
| B. | limited space charge accumulation mode |
| C. | stable amplification mode |
| D. | bias circuit oscillation mode |
| Answer» B. limited space charge accumulation mode | |
| 9. |
When either a voltage or current is applied to the terminals of bulk solid state compound GaAs, a differential ______ is developed in that bulk device? |
| A. | negative resistance |
| B. | positive resistance |
| C. | negative voltage |
| D. | none of the mentioned |
| Answer» B. positive resistance | |
| 10. |
The electrodes of a Gunn diode are made of: |
| A. | molybdenum |
| B. | GaAs |
| C. | gold |
| D. | copper |
| Answer» B. GaAs | |
| 11. |
GaAs is used in fabricating Gunn diode. Gunn diode is: |
| A. | bulk device |
| B. | sliced device |
| C. | made of different type of semiconductor layers |
| D. | none of the mentioned |
| Answer» B. sliced device | |
| 12. |
When the applied electric field exceeds the threshold value, electrons absorb more energy from the field and become: |
| A. | hot electrons |
| B. | cold electrons |
| C. | emission electrons |
| D. | none of the mentioned |
| Answer» B. cold electrons | |
| 13. |
When the electric field applied to GaAs specimen is less than the threshold electric field, the current in the material: |
| A. | increases linearly |
| B. | decreases linearly |
| C. | increases exponentially |
| D. | decreases exponentially |
| Answer» B. decreases linearly | |
| 14. |
In a GaAs n-type specimen, the current generated is constant irrespective of the electric filed applied to the specimen. |
| A. | true |
| B. | false |
| Answer» C. | |
| 15. |
GaAs is used in the fabrication of GUNN diodes because: |
| A. | GaAs is cost effective |
| B. | It less temperature sensitive |
| C. | it has low conduction band electrons |
| D. | less forbidden energy gap |
| Answer» E. | |
| 16. |
Silicon and germanium are called ___________ semiconductors. |
| A. | direct gap |
| B. | indirect gap |
| C. | band gap |
| D. | indirect band gap |
| Answer» C. band gap | |