USING TRANSFORMERS TO CHANGE VOLTAGES
3 marks · EasyA step-down transformer has 900 turns on its primary coil and 90 turns on its secondary coil. The primary voltage is 225 V.
Calculate the secondary voltage.
State one use for a step-down transformer.
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(a) 22.5 V
(b) To reduce mains voltage for safe use in devices · must show Safe voltage for devices, Mains voltage reduction
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Marking points
M1 (a) · 1 mark · Uses transformer equation:
A1 (a) · 1 mark · Gives
B1 (b) · 1 mark · States any practical use of a step-down transformer (e.g., adapting mains voltage for domestic use, chargers, etc.).
Worked solution
A step-down transformer is used to reduce the voltage, for example, to supply safe voltage to household devices or low-voltage electronics.