GravitationNEET Physics · Class 11 · NCERT Chapter 7

At what height above the Earth's surface does $g$ become $1/4$ of its surface value? Take Earth's radius $R$.

The value of $g$ at depth $d$ below Earth's surface is half its surface value. The depth is:

Two satellites of the same planet have orbital radii $r_1$ and $r_2=4r_1$. The ratio of their periods is:

The escape velocity from a planet is $v$. If both the mass and radius of the planet are doubled, the new escape velocity is:

The escape velocity at Earth's surface is $11.2\text{km/s}$. The escape velocity from a planet whose mass is $9M$ and radius is $4R$ (where $M$, $R$ refer to Earth) is:

A satellite is at a height equal to Earth's radius above the surface. Its orbital velocity is:

The orbital velocity of a satellite very close to the Earth's surface (low orbit) is approximately:

The total energy of a satellite of mass $m$ in a circular orbit of radius $r$ around a planet of mass $M$ is:

The work done in lifting a body of mass $m$ from Earth's surface to a height equal to $R$ (Earth's radius) is:

A planet revolves around the Sun in an elliptical orbit. The areal velocity (area swept per unit time) is:

The gravitational force between two point masses is $F$. If the distance between them is doubled, the new force is:

The gravitational force between two masses each of $1\text{kg}$ separated by $1\text{m}$ is:

A geostationary satellite has a time period of:

At the centre of the Earth, the value of $g$ is:

The Moon orbits Earth with period $T$ at radius $r$. A satellite at radius $r/4$ has period:

The gravitational potential at the surface of Earth (taking infinity as zero) is:

Two satellites $A$ and $B$ are at heights $h$ and $3h$ above Earth (radius $R$) respectively. The ratio of their orbital velocities $v_A/v_B$ is (assume $h\ll R$):

The escape velocity does NOT depend on:

Kepler's law of orbits states that planetary orbits are:

To free a satellite of mass $m$ from a circular orbit of radius $r$, the minimum extra energy required is:

Two solid spheres of equal mass $M$ and radius $R$ touch each other. The gravitational force between them is:

A body weighs $90\text{N}$ on the surface of Earth. Its weight at a height equal to half of Earth's radius is:

The gravitational potential energy of a body of mass $m$ on Earth's surface (taking infinity as zero) is:

A satellite is launched into a circular orbit at a height equal to Earth's radius. The minimum additional kinetic energy needed to make it escape is (mass of satellite $m$):

A geostationary satellite is in equatorial orbit. Its altitude above Earth's surface is approximately:

If the Earth suddenly shrinks (mass conserved) to half its present radius, the time period of revolution around the Sun would:

Three equal masses $m$ are placed at the corners of an equilateral triangle of side $a$. The gravitational force on any one mass due to the other two is:

The kinetic energy of a satellite in a circular orbit is $K$. Its total energy is:

The minimum energy required to launch a body of mass $m$ from Earth's surface and place it in a circular orbit at height $h=R$ above the surface is:

Two planets have radii $R$ and $2R$ but the same average density. The ratio of their accelerations due to gravity at the surface is:

If $T$ is the period of a satellite in a circular orbit close to Earth's surface, the orbital velocity is: