A particle of mass M is suited at the centre of a spherical shell of same mass and radius a. The gravitational potential at a point situated at a/2 distance from the centre, will be: […]
The radii of circular orbits of two satellites A and B of the earth, are 4R and R respectively. If the speed of satellite A is 3 V, then the speed of satellite B will […]
Two satellites of earth, S₁ and S₂ are moving in the same orbit. The mass of S₁ is four times the mass of S₂. Which one of the following statements is true?
Options
The kinetic energy needed to project a body of mass m from the surface of earth (radius R) to infinity is
Options
(a) mgR/2 (b) 2mgR (c) mgR (d) mgR/4
Correct Answer:
mgR
Two planets at mean distances d₁ and d₂ from the sun have their frequencies n₁ and n₂ respectively. Then
Options
(a) n₁²d₁²=n₂²d₂² (b) n₁²d₁³=n₂²d₂³ (c) n₁d₁²=n₂d₂² (d) n₁²d₁=n₂²d₂
Correct Answer:
n₁²d₁³=n₂²d₂³
Explanation:
Apply […]
The ratio of radii of planets A and B is K₁ and ratio of accelerations due to gravity on them is K₂. The ratio of escape velocities from them will be
Options
(a) […]
The acceleration due to gravity near the surface of a planet of radius R and density d is proportional to
Options
(a) d/R² (b) dR² (c) dR (d) d/R
Correct Answer:
dR
Explanation: […]
A satellite is launched into a circular orbit of radius R around earth while a second satellite is launched into an orbit of radius 1.02R. The percentage difference in the time periods of the two […]
If the density of earth is doubled keeping its radius constant then acceleration due to gravity will be (g=9.8 m/s²)
Options
(a) 19.6 m/s² (b) 9.8 m/s² (c) 4.9 m/s² (d) 2.45 m/s²
The input signal given to a CE amplifier having a voltage gain of 150 is Vi=2 cos (15t+π/3). The corresponding output signal will be
Options
(a) 75 cos(15t+2π/3) (b) 2 cos(15t+5π/6) (c) 300 […]
2017 Copyright Doctor Dreams Training Academy