Transformer
calculations

Higher GCSE paper only


1	A transformer has 200 turns on its primary coil, and 50 on its secondary coil. This is a:-
		Step-up transformer
		Step-down transformer




2	A transformer has a primary coil of 100 turns and a secondary coil of 300 turns. What will be the voltage out of the secondary coil if we apply 20 V to the primary?
		300V
		33V
		60V
		40V


3	If we need to change 240 V down to 12 V, and our transformer to has 2000 turns on its primary coil, how many turns should it have on its secondary coil?
		100 turns
		240 turns
		12 turns
		2880 turns


4	The mains voltage varies from country to country. A battery charger for a 6 Volt camcorder battery has 4000 turns on its primary coil and 100 turns on its secondary. Is this charger made for use in the U.K, where the mains supply voltage is 240V, or for the island of Kludge, where the supply is at 120V?
		Made for U.K.
		Made for Kludge