Energy And Efficiency

Question 1

Name the different forms of energy.

Answer 1

magnetic
kinetic (movement energy)
heat (thermal energy)
light
gravitational potential
chemical
sound
electrical
elastic potential
nuclear.

Question 2

How do you calculate energy efficiency?

Answer 2

The efficiency of a device such as a lamp can be calculated:
efficiency = useful energy out ÷ total energy in (for a decimal efficiency)
efficiency = (useful energy out ÷ total energy in) × 100 (for a percentage efficiency)
The efficiency of the filament lamp is 10 ÷ 100 = 0.10 (or 10 percent).
This means that 10 percent of the electrical energy supplied is transferred as light energy (90 percent is transferred as heat energy).