*
The average value of a function F (t) over a period T is given by F t
T
F t
t
T
( )
( )
=
∫
1
0
d
** <
> =
∫
=


=
−
[
] =
cos
cos
sin
sin
2
1
2
1
22
21
2
0
0
0
0
ω
ω
ωω
ω
ω
t
T
t dt
T
t
T
T
T
T
FIGURE 7 3 The rms current I is related to the
peak  current im by I = 
mi/ 2
 = 0 707 im Rationalised 2023-24
Physics
180
It is defined by
2
212
2
m
m
i
I
i
i
=
=
=
= 0