Physics Questions

Rolling friction or rolling drag is the force resisting the motion when a body rolls on a surface. It is mainly caused by non-elastic effects, that is, not all the energy needed for deformation of the wheel, roadbed, etc... is recovered when the pressure is removed.

Another cause of rolling resistance lies in the slippage between the wheel and the surface, which dissipates energy.

Energy can be either a potential energy or a kinetic energy.

The energy associated with motion is called Kinetic energy and it can be stored. And the energy associated with position is called Potential energyand it cannot be stored.

The water rise in a capillary tube dipped in water is such that the weight of water in the tube above the surface of water in the vessel is equal to (balances) the upward force due to surface tension. So it is clear that if the the bore (radius) to the tube is decreased, the height of the water column in it must be greater.  So, (a) is correct.

Cohesion refers to attraction between molecules of the same kind while adhesion refers to attraction between different kinds of molecules

Heat transfer through radiation takes place in form of electromagnetic waves mainly in the infrared region. It depends on nature of the body, its temperature and kind & extent of its surface.

In VIBGYOR. It has colors ordered from highest to lowest frequency.

              Violet > Indigo > Blue > Green > Yellow > Orange > Red

That says Violet has the highest frequency.

We know, Speed of light = Frequency x Wavelength

=> As frequeny is inversely proportional to wavelength i.e, as frequwncy goes high wavelength goes down.

So, the violet color has the highest frequency.