6.20 know and use the relationship: input power = output power
input power = output power
since power = current x voltage
Vp x Ip = Vs x Is
p = primary, s = secondary
when a voltage of 12V is applied across the primary coil of a step-down transformer, a current of 0.4A flows through the primary coil. calculate the current flowing through the secondary coil if the voltage induced across it is 2V. assume that the transformer is 100% efficient
12V x 0.4 = 2 x Is
I = (12 x 0.4) / 2
I = 2.4A












