61.
In a photocell light energy is converted into

62.
A voltaic cell converts chemical energy to

63.
The work done by the string of a simple pendulum during one complete oscillation is equal to

64.
Conversion of sound energy into electrical energy is done by

65.
If a person moves a trolley for a distance of 10 m with a force of 50 N, then the work done is

66.
Necessary element of change in solar energy to electrical energy

67.
In hydro power station, the motion produced in turbines is due to

69.
In a rechargeable cell what kind of energy is stored within the cell?

70.
A bullet is fired from a rifle which recoils after firing. The ratio of kinetic energy of the rifle to that of the bullet is