A transformer has an efficiency of 75%. It has 4000 turns on its primary coil and 100 turns on its secondary coil. When the primary of the transformer is connected to a 240 V ac supply, the secondary current is 12.0 A. What are the primary current and secondary voltage?
Primary current = 400 mA400\text{ mA}400 mA, Secondary voltage = 6.0 V6.0\text{ V}6.0 V
Primary current = 225 mA225\text{ mA}225 mA, Secondary voltage = 6.0 V6.0\text{ V}6.0 V
Primary current = 400 mA400\text{ mA}400 mA, Secondary voltage = 9600 V9600\text{ V}9600 V
Primary current = 225 mA225\text{ mA}225 mA, Secondary voltage = 9600 V9600\text{ V}9600 V
66 exam-style questions on AQA A Level Physics Magnetic fields (A-level only), covering Magnetic flux density (A-level only), Moving charges in a magnetic field (A-level only), Magnetic flux and flux linkage (A-level only), Electromagnetic induction (A-level only), Alternating currents (A-level only), and The operation of a transformer (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.