Question : Which of the following is an example of contact force?

Option 1: Electrostatic force

Option 2: Muscular force

Option 3: Gravitational force

Option 4: Magnetic force

Question : In a water-lifting electric pump, we convert

Option 1: electrical energy into potential energy

Option 2: kinetic energy into electrical energy

Option 3: kinetic energy into potential energy

Option 4: electrical energy into kinetic energy

Question : What type of energy conversion takes place in a battery?

Option 1: Chemical energy into light energy

Option 2: Chemical energy into electrical energy

Option 3: Mechanical energy into chemical energy

Option 4: Chemical energy into sound energy

Question : If the momentum of a body is doubled, the kinetic energy is:

Option 1: becomes 1/4 times

Option 2: unchanged

Option 3: doubled

Option 4: becomes 4 times

Question : The SI unit of power of the lens is ________.

Option 1: candela

Option 2: mole

Option 3: watt

Option 4: dioptre