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Question: Answered & Verified by Expert
Assertion : LASER is used to measure distant object as moon.
Reason : They are highly coherent source of light.
PhysicsWave OpticsAIIMSAIIMS 2001
Options:
  • A If both $A$ and and Reason are true and Reason is the correct explanation of Assertion.
  • B If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
  • C If Assertion is true but Reason is false.
  • D If Assertion is false but Reason is true.
Solution:
1413 Upvotes Verified Answer
The correct answer is: If both $A$ and and Reason are true and Reason is the correct explanation of Assertion.
As LASER is highly monochromatic and highly coherent, we can send a LASER beam to the moon, from where it comes back reflected without much loss of intensity. That's why the large distances can be measured accurately with the help of LASER.

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