use-
ful description the electrical effects a.
FIGURE 4.7
Unidirectional and alternating supply.c.Basic Electrical Installation Work
94
In the United Kingdom generate electricity frequency 50Hz and
the time taken complete each cycle given by
T
f
T
1
1
50
0 02
⬖
Hz
s
. waveform can given by
the maximum, average and rms values the waveform.
. Cable and equipment insulation levels must
be equal greater than this value.c.
V
V
V
0
0
Battery supply d.
Mains supply a.c.
The maximum peak value the greatest instantaneous value reached
by the generated waveform.8
Characteristics sine wave.
90 Vmax peak value
V
30
0
0 180
Period )
Time (s)
270 360
vinstantaneous values
360
330
300
270
240
210
180
150
120
North pole
South pole
Rotating
coil
60
FIGURE 4.
An alternating waveform constantly changing from zero maxi-
mum, first one direction, then the opposite direction, and the
instantaneous values the generated voltage are always changing
