CBSE  /  Class 11  /  Physics  /  Chapter 8 Gravitation

  • 1. 
    The value of g at a particular point is 9.8 m/sec² suppose the earth suddenly shrink uniformly to half its present size without losing any mass. The value of g at the same point (assuming that the distance of the point from the centre of the earth does not shrink) will become

  • 9.8 m/sec²
  • 4.9 m/sec²
  • 19.6 m/sec²
  • 2.45 m/sec²

  • 2. 
    A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is

  • Positive
  • Negative
  • Zero
  • may be positive or negative

  • 3. 
    If the radius of the earth were to be raise by 1% its mass remaining the same, the acceleration due to gravity on the surface of the earth will

  • increase by 1%
  • decrease by 2%
  • decrease by 1%
  • increase by 2%

  • 4. 
    A body is projected vertically from the surface of the earth of radius R with velocity equal to half of the escape velocity. The maximum height reached by the body is

  • R
  • R/2
  • R/3
  • R/4

  • 5. 
    The escape velocity of projection from the earth is approximately (R = 6400 km)

  • 7 km/sec
  • 112 km/sec
  • 12.2 km/sec
  • 1.1 km/sec

  • 6. 
    Who among the following first gave the experimental velocity of G?

  • Cavendish
  • Copernicus
  • Brook Taylor
  • none of these

  • 7. 
    A satellite S is move in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth .

  • The acceleration of S is always directed towards the centre of the earth.
  • The angular momentum of S about the centre of the earth changes in direction, but its magnitude remains constant.
  • The total mechanical energy of S varies periodically with time.
  • The linear momentum of S remains constant in magnitude.

  • 8. 
    The mean radius of the earth is R, its angular speed on its own axis is w and the acceleration due to gravity at earths surface is g. The cube of the radius of the orbit of a geo-stationary satellite will be

  • r²g / w
  • R²w²/ g
  • RG w²
  • R²g / w²

  • 9. 
    If the distance between the earth and the sun were half its present value, the number of day in a year would have been

  • 64.5
  • 129
  • 182.5
  • 730

  • 10. 
    The masses of two planets are in the ratio 1 : 2. Their radii are in the ratio 1 : 2. The acceleration due to gravity on the planets are in the ratio.

  • 1 : 2
  • 2 : 1
  • 3 : 5
  • 5 : 3
Report Question
warning
Practice More On Chapter 8 Gravitation
Quiz 1 Quiz 2
access_time
  Time