1. Transformers Answer Q1 and 2

2. Transformers

3. Recap - Changing Voltages
The ratio of the number of turns on the coils equals the ratio of the voltages
# of turns = Ns
# of turns = Np
Vp/Vs = Np/Ns

4. Question

5. Practical Transformers
Most practical transformers have the two coils on top of one another rather than side by side
The core is laminated to reduce eddy currents and made of soft iron to allow easy magnetic reversals
Often transformers have multiple outputs allowing many voltages to be tapped off
Transformers are very efficient but larger ones require cooling (usually with oil) hence we can often assume that:
Power in = power out or
Vin Iin= Vout Iout or VPIP=VSIS