CBSE
The condition for a uniform spherical mass m of radius r to be a black hole is [ G = gravitational constant and g = acceleration due to gravity ]
The orbital velocity of an artificial satellite in a circular orbit above the earth's surface at a distance equal to radius of earth is v. For a satellite orbiting at an altitude half of earth's radius, orbital velocity is
v
v
v
Kepler's second law is based on
Newton's first law
special theory of relativity
Newton's second law
Conservation of angular momentum
If vο be the orbital velocity of satellite in a circular orbit close to the earth's surface and ve is the escape velocity from the earth, then relation between the two is
vο = ve
ve =
ve = vο
ve = 2 vο
Assertion: Planet is a heavenly body revolving round the sun.
Reason: Star is luminous body made of gaseous material.
If both the assertion and reason are true and reason is a correct explanation of the assertion.
If both assertion and reason are true but assertion is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both assertion and reason are false.
Escape velocity of a rocket is 11.2 km/sec. It is released at an angle of 45°. Its escape velocity is
11.2 m/sec
11.2 km/sec
11.2 km/sec
22.3 km/sec
The equivalent resistance between A and C of the given circuit, is
8 Ω
Ω
Ω
The velocity with which a projectile must be fired so that it escapes earth's gravitation does not depend on
mass of the earth
mass of the projectile
radius of the projectile's orbit
gravitational constant
What is the dimensional formula for the gravitational constant?
[ M-1 L3 T-2 ]
[ M-1 L3 T-1 ]
[ M-2 L3 T-2 ]
[ M-2 L-1 T3 ]
Hubble's law is related with
comet
speed of galaxy
black hole
planetary motion