Q.1
The earth ( mass=6 × 1024kg) revolves around the sun with an angular velocity 2 × 10⁻⁷ rad/sec in a circular orbit of radius=1.5 × 108km. The force exerted by sun on earth in newton is ...[ AFMC 1997, 1999]
  • a)36 × 1021
  • b) 18 × 1025
  • c)29 × 1039
  • d)zero
Q.2
A particle of mass 10g is kept on the surface of a uniform sphere of mass 100kg and radius 10cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere ( G=6.67 × 10⁻¹¹ Nm2 / kg2) [ AIEEE 2005]
  • a) 3.33 × 10⁻¹⁰ J
  • b) 13.34 × 10⁻¹⁰ J
  • c)6.67× 10⁻¹⁰ J
  • d)6.67× 10⁻⁹ J
Q.3
The gravitational potential energy of a rocket of mass 100kg at a distance 109 m from earth surface is 4 × 107 joule. The weight of the rocket in Newton's at distance 109 m from earth is ( Re=6400 km)
  • a) 8 ×10⁻² N
  • b) 8 × 10⁻³ N
  • c)4 × 10⁻³ N
  • d)4 × 10⁻²N
Q.4
The speed of earth's rotation about its axis is ω. Its speed increases to x times to make the effective acceleration due to gravity equal to zero at the equator. Then x is ..
  • a)1.7
  • b) 8.5
  • c)17
  • d)3.4
Q.5
A black hole is an object whose gravitationalfield is so strong that even light cannot escapefromit.To what approximateradiuswouldearth(mass = 5.98 × 1024 kg) have to becompressed to be a black hole?
  • a) 10–2 m
  • b) 100m
  • c) 10–9 m
  • d) 10–6 m
Q.6
The earth ( mass=6 × 1024kg) revolves around the sun with an angular velocity 2 × 10⁻⁷ rad/sec in a circular orbit of radius=1.5 × 108km. The force exerted by sun on earth in newton is ...[ AFMC 1997, 1999]
  • a)36 × 1021
  • b) 18 × 1025
  • c)29 × 1039
  • d)zero
Q.7
A particle of mass 10g is kept on the surface of a uniform sphere of mass 100kg and radius 10cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere ( G=6.67 × 10⁻¹¹ Nm2 / kg2) [ AIEEE 2005]
  • a) 3.33 × 10⁻¹⁰ J
  • b) 13.34 × 10⁻¹⁰ J
  • c)6.67× 10⁻¹⁰ J
  • d)6.67× 10⁻⁹ J
Q.8
The gravitational potential energy of a rocket of mass 100kg at a distance 109 m from earth surface is 4 × 107 joule. The weight of the rocket in Newton's at distance 109 m from earth is ( Re=6400 km)
  • a) 8 ×10⁻² N
  • b) 8 × 10⁻³ N
  • c)4 × 10⁻³ N
  • d)4 × 10⁻²N
Q.9
The speed of earth's rotation about its axis is ω. Its speed increases to x times to make the effective acceleration due to gravity equal to zero at the equator. Then x is ..
  • a)1.7
  • b) 8.5
  • c)17
  • d)3.4
Q.10
A black hole is an object whose gravitationalfield is so strong that even light cannot escapefromit.To what approximateradiuswouldearth(mass = 5.98 × 1024 kg) have to becompressed to be a black hole?
  • a) 10–2 m
  • b) 100m
  • c) 10–9 m
  • d) 10–6 m
0 h : 0 m : 1 s