The rechargeable batteries for a laptop computer need a much smaller voltage than what a wall socket provides. Therefore, a transformer is plugged into the wall socket and produces the necessary voltage for charging the batteries. The batteries are rated at 9.0 V, and a current of 200 mA is used to charge them. The wall socket provides a voltage of 120 V.
(a) Determine the turns ratio of the transformer.
Ns
Np
(b) What is the current coming from the wall socket?
Ip =
(c) Find the average power delivered by the wall socket and the average power sent to the batteries.
Pp =
Ps =