alternating current Flashcards
(10 cards)
1
Q
define alternating current (no need to memorise)
A
current which periodically vary from positive to negative and changes its magnitude continuously with time
2
Q
what same is current-time or voltage-time graph of AC
A
sinusoidal (sin shape)
3
Q
what is peak current (I0) or voltage (V0)
A
the maximum current of voltage of AC
4
Q
equation of alternating current with respect to time
A
I = I0 sin(ω *t)
I=current at time
t=time
I0=peak current
ω=angular frequency (same a SHM)
5
Q
equation alternating voltage
A
V = V0* sin(ωt)
6
Q
why is r.m.s current useful
A
- can compare AC to DC
- calculate amount of power dissipated
7
Q
what root mean square current
A
the value of a DC current that produces the same amount of energy as AC in a resistor
8
Q
equation r.m.s. current
A
I(r.m.s) = I0/√2
I0=peak current
9
Q
equation Vr.m.s
A
Vr.m.s = V0/√2
10
Q
A
