MCQOPTIONS
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MCQOPTIONS
This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering Physics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In Stimulated emission, the emitted photons are _____________ |
| A. | Coherent and Monochromatic |
| B. | Non-coherent and monochromatic |
| C. | Coherent and Non-Monochromatic |
| D. | Non-Coherent and Non-monochromatic |
| Answer» B. Non-coherent and monochromatic | |
| 2. |
For an ordinary light source, the coherence time t = 10-10s. The degree of Monochromaticity for a wavelength of 6000 is ___________ |
| A. | 0.1 X 10<sup>-4</sup> |
| B. | 0.2 X 10<sup>-4</sup> |
| C. | 0.3 X 10<sup>-4</sup> |
| D. | 0.4 X 10<sup>-4</sup> |
| Answer» C. 0.3 X 10<sup>-4</sup> | |
| 3. |
Laser light from a 7mW source of aperture diameter 1.5 cm and wavelength 5000 is focused by a lens of focal length 10 cm. The intensity of the image is __________ |
| A. | 3 X 10<sup>7</sup> Wm<sup>-2</sup> |
| B. | 4 X 10<sup>7</sup> Wm<sup>-2</sup> |
| C. | 5 X 10<sup>7</sup> Wm<sup>-2</sup> |
| D. | 6 X 10<sup>7</sup> Wm<sup>-2</sup> |
| Answer» D. 6 X 10<sup>7</sup> Wm<sup>-2</sup> | |
| 4. |
The output of a laser has pulse duration of 20 ms and average output power of 1.75 W per pulse. How much energy is released per pulse if wavelength is 5890 ? |
| A. | 0.011 J |
| B. | 0.024 J |
| C. | 0.035 J |
| D. | 0.047 J |
| Answer» D. 0.047 J | |
| 5. |
What is the general lifetime of an atom in an exited state? |
| A. | 10<sup>-10</sup> |
| B. | 10<sup>-8</sup> |
| C. | 10<sup>-6</sup> |
| D. | 10<sup>-4</sup> |
| Answer» C. 10<sup>-6</sup> | |
| 6. |
The frequency of incident photon so that the atom makes a transition from E1 to E2 should be __________ |
| A. | E<sub>2</sub> E<sub>1</sub> |
| B. | E<sub>2</sub> E<sub>1</sub>/c |
| C. | E<sub>2</sub> E<sub>1</sub>/h |
| D. | E<sub>2</sub> E<sub>1</sub>/ |
| Answer» D. E<sub>2</sub> E<sub>1</sub>/ | |
| 7. |
Phonons are __________ |
| A. | Quanta of energy |
| B. | Quanta of light waves |
| C. | Quanta of sound waves |
| D. | Quanta of heat |
| Answer» D. Quanta of heat | |
| 8. |
Photons emitted by spontaneous emission are __________ |
| A. | Coherent and Monochromatic |
| B. | Non-coherent and monochromatic |
| C. | Coherent and Non-Monochromatic |
| D. | Non-Coherent and Non-monochromatic |
| Answer» E. | |