The efficient use of energy

NAME:.......................



1. In traditional filament light bulbs a lot of energy is wasted as ...........................



2. Give TWO reasons why this wasted energy contributes to global warming.

(a) ...............................

(b) ...............................



3. Petrol engines are inefficient because energy is wasted as:

(a) .............................................................. and (b) ..............................................................



4. A light bulb is designed to convert ............................... energy into ............................... energy.



5. Write down the law of conservation of energy.

..............................................................



6. Write down the energy transfer when electrical energy from a battery is used to run an electric motor that lifts a load.

Electrical energy is converted to ...............................

(b) which of the energy types that you have written down can be considered as ‘wasted’ energy?

.........................................................



7. Where does this wasted energy go? ...............................



8. What is the result of this ‘wasted’ energy?...............................



9. What is meant by the “heat death of the Universe”? (Hint: spreading out of energy)

..............................................................



10. Efficient machines are ones that transform .......................... percentages of the input energy

into .........................forms of output energy.