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NTA Abhyas JEE Main2020PhysicsGravitationPractice

A spherical hole is made in a solid sphere of radius R . The mass of the sphere before hollowing was M . The gravitational field at the centre of the hole due to the remaining mass is

Options

  1. AZero
  2. BGM 8 R 2
  3. CGM 2 R 2
  4. DGM R 2

Correct answer

C. GM 2 R 2

Step-by-step solution

By the principle of superposition of fields E → = E → 1 + E → 2 Here, E → = net field at the centre of hole due to entire mass E → 1 = field due to remaining mass and E → 2 = field due to mass in hole = 0 ∴ E 1 = E = GM R 3 . r where r = R 2 ∴ E = GM 2 R 2

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