Efficiency Year 10 Physics

Front

What is efficiency in physics?

Back

Efficiency is the ratio of useful output energy to the total input energy, often expressed as a percentage.

Front

How do you calculate efficiency?

Back

Efficiency (%) = (Useful Output Energy / Total Input Energy) x 100

Front

If a machine has an efficiency of 75% and uses 200J of energy, how much energy is wasted?

Back

50J is wasted.

Front

What is the unit of efficiency?

Back

Efficiency is often expressed as a percentage.

Front

What is the energy transformation in a car engine?

Back

Chemical energy from fuel is transformed into mechanical energy.

Front

What is the energy transformation in a solar panel?

Back

Solar energy is transformed into electrical energy.

Front

What is the energy transformation in a light bulb?

Back

Electrical energy is transformed into light energy.

Front

What is the energy transformation in a battery?

Back

Chemical energy is transformed into electrical energy.

Front

What is the unit of energy?

Back

The unit of energy is the Joule (J).

Front

If a solar panel receives 10J of energy and outputs 1.2J, what is its efficiency?

Back

Efficiency = (1.2J / 10J) x 100 = 12%.