Height of geostationary satellite is

• 16000 km

• 22000 km

• 28000 km

• 36000 km

If a solid sphere of mass 1 kg and radius 0.1 m rolls without slipping at a uniform velocity of I m/s along a straight line on a horizontal floor, the kinetic energy is

• $\frac{7}{5}$ J

• $\frac{2}{5}$ J

• $\frac{7}{10}$ J

• 1 J

In the diagram shown below all three rods are of equal length Land equal mass M. The system is rotated such that rod B is the axis. What is the moment of inertia of the system?

• $\frac{{\mathrm{ML}}^2}{6}$

• $\frac{4}{3}$ML²

• $\frac{{\mathrm{ML}}^2}{3}$

• $\frac{2}{3} {\mathrm{ML}}^2$

The direction of the angular velocity vector is along

• the tangent to the circular path

• the inward radius

• the outward radius

• the axis of rotation

A man of mass 60 kg records his wt on a weighing machine placed inside a lift. The ratio of wts. of  man recorded when lift is ascending up with a uniform speed of 2 m/s to when it is descending down with a uniform speed of 4 m/s will be

• 0.5

• 1

• 2

• none of these

The force of gravitation is

• repulsive

• conservative

• electrostatic

• non-conservative

Which of the following velocity-time graphs shows a realistic situation for a body in motion?

Assertion:  An astronaut experience weightlessness in a space satellite. 

Reason:  When a body falls freely it does not experience gravity.

• If both assertion and reason are true and reason s the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Shear modulus is zero for

• solids

• liquids

• gases

• liquids and gases

If the temperature of a black body increases from 7°C to 287°C then the rate of energy radiation increases by

• ${\left(\frac{287}{7}\right)}^4$

• 16

• 4

• 2