2.5 Conservation of energy(Revision)

Energy can disappear.

• True

• False

The law mentioned below is called........................................

“energy cannot be created or destroyed”.

• Law of conservation of energy

• Newton's second law of energy

• Archimedes law

When you turn on a lamp, all of the electrical energy is changed into........................................................... and.........................................

• light energy

• sound energy

• chemical energy

• thermal energy

When you turn on a light which of the following produced energy is wasted energy?

• light energy

• sound energy

• chemical energy

• thermal energy

When you turn your car engine, all of the chemical energy in the fuel changes into.....................................and .........................................

• light energy

• movement energy

• upthrust energy

• thermal energy

When you turn your car engine, all of the chemical energy in the fuel changes into useful energy, name it.

• movement energy

• sound energy

• chemical energy

• thermal energy

............................................ is produced in many machines because there is friction between moving parts.

• Gravitational energy

• Chemical energy

• Thermal energy

Thermal energy can be transferred to the surroundings.

• True

• False

In some home appliance, the same type of energy is wasted as is useful like in...........................

• car engines

• electric kettles

• torches

The efficiency of a machine or device tells you how much of the energy that the machine produces as wasted energy.

• False

• True