## Electromagnetism Questions

## Transformers Questions

EASY 1.A transformer has 10 turns on its primary coil and 30 turns on the secondary. If the primary voltage is 2 V, what is the secondary voltage? 2. A transformer has 20 turns on the primary coil and 2 turns on the secondary. If the primary voltage is 100 V, what is the secondary voltage? MEDIUM 3. A transformer is being used to play a game boy. Mains electricity is 220 V and the gameboy needs 6 V. If the transformer has 10 coils on its secondary coil, how many does it have on its primary? 4. Explain why electricity is transmitted at very high voltages. HARD 5. An ideal transformer has 40 turns on its secondary coil and 3200 turns on its primary. i. Calculate the secondary voltage if a 220 V a.c. supply is connected to the primary coil ii. Calculate the current through a 15 Ohm resistor connected to the secondary coil. iii. What current must flow through the primary coil when the 15 Ohm resistor is connected to the secondary coil? iv. What would be the answer to i. Be if a d.c. supply was used instead? |