Practice Transformer in Physics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
A device that changes the voltage of alternating current by using two coils wound around a shared iron core.
A transformer trades voltage for current (or vice versa) — like a gear system trades speed for torque.
Example 1
easyA step-up transformer has 100 turns on the primary coil and 500 turns on the secondary coil. If the input voltage is 240 \text{ V}, what is the output voltage?
Example 2
mediumAn ideal transformer steps down 11{,}000 \text{ V} to 220 \text{ V}. If the secondary current is 50 \text{ A}, what is the primary current?
Example 3
mediumA phone charger transformer converts 240 \text{ V} AC to 5 \text{ V} AC. If the primary coil has 960 turns, how many turns does the secondary coil have?
Example 4
hardA transformer with 90\% efficiency steps up 240 \text{ V} to 12{,}000 \text{ V}. If the secondary delivers 2 \text{ A}, what is the primary current and the power wasted as heat?