electrical energy Flashcards
1
Q
energy cant be
A
created or destroyed
2
Q
energy can be
A
transformed from 1 form into another
3
Q
power is measured in
A
watts
4
Q
calculating electrical power:
A
P = VI = I squared R = V squared divded by R
5
Q
direct current causes charge to move in
A
one direction
6
Q
alternating current causes charge to move in
A
one way then the other
7
Q
a supply with a constant voltage (e.g. a battery) is a
A
direct current supply
8
Q
mains electricity is an
A
a.c supply
9
Q
mains supply =
A
230V
10
Q
the frequency of mains supply=
A
50 Hz-
11
Q
appliances of power up to 720W usually need a
A
3A fuse
12
Q
appliances of power more than 720W usually need a
A
13A fuse
