MCQ
The light source will be coherent if :
- ✓The phase difference remains fixed at their place of origin
- BThey should have the same amplitude
- CTheir frequency should be same
- DAll the above mentioned things are present.
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| List$-I$ (Layer of atmosphere) | List$-II$ (Approximate height over earth's surface) |
| $(A)$ $F_1$ - Layer | $(I)$ $10\,km$ |
| $(B)$ $D-$ Layer | $(II)$ $170-190\,km$ |
| $(C)$ Troposphere | $(III)$ $100\,km$ |
| $(D)$ $E-$layer | $(IV)$ $65-75\,km$ |
Choose the correct answer from the options given below: