Question

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 195 mA is used to charge them. The wall socket provides a voltage of 120 V. Determine the turns ratio of the transformer.

Answer 1

The turns ratio of the transformer for the laptop charger is determined by dividing the wall socket voltage (120 V) by the required battery voltage (9.0 V), resulting in a turns ratio of 13.33.

Step-by-step explanation:

The student's question involves determining the turns ratio of a transformer used in a laptop computer charger. To find the turns ratio, we look at the relationship between the input voltage (from the wall socket) and the output voltage needed to charge the batteries. Since the transformer's role is to step down the voltage from the wall socket (120 V) to that required by the laptop batteries (9.0 V), the turns ratio can be found by dividing the input voltage by the output voltage. The turns ratio of the transformer is therefore 120 V divided by 9.0 V, which equals 13.33 (to 2 decimal places).