3.2 Electrical Power Flashcards Preview

GCSE Physics 1.3 Electrical Energy > 3.2 Electrical Power > Flashcards

Flashcards in 3.2 Electrical Power Deck (8):
1

What is the power of an appliance?

The rate at which is transfers energy

2

What is powers unit?

Watt, W

3

Why do we sometimes use kilowatts instead of watts?

Watts are too small a unit to be useful

4

What is the equation for power?

P=e/t

Where
P is the power in watts
E is the energy transferred in joules
T is the time in seconds

5

How can we work out the efficiency of power?

Efficiency = useful power out / total power in

x100 for a %

6

What is 1 watt equivalent to?

1 joule per second

7

An electric motor transfers 48kJ of electrical energy into kinetic energy in 2 minutes. What is the useful power out of the motor?

400W

8

What is power?

The amount of energy transferred per second