NEET Solved Paper 2019 Question 28

Question: The work done to raise a mass m from the surface of the earth to a height h, which is equal to the radius of the earth, is: [NEET 5-5-2019]

Options:

A) $ \frac{1}{2}mgR $

B) $ \frac{3}{2}mgR $

C) $ mgR $

D) $ 2mgR $

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Answer:

Correct Answer: A

Solution:

  • $ \Delta PE=\frac{GMm}{r _1}-\frac{GMm}{r _2} $ $ \frac{GMm}{R}-\frac{GMm}{2R} $ $ \frac{GMm}{2R}-\frac{mgR}{2} $