A transformer has 1000 turns on the primary side and 500 on the secondary. What is the output if the input is 120v?

A transformer has 1000 turns on the primary side and 500 on the secondary. What is the output if the input is 120v?

• A. 240 V
• B. 120 V
• C. 480 V
• D. 60 V

Answer: (D)

Voltage in a transformer is determined by the turns ratio between the primary and secondary windings. The secondary voltage equals the primary voltage times the secondary turns divided by the primary turns. Here, there are 1000 turns on the primary and 500 on the secondary, so the ratio Ns/Np is 500/1000 = 0.5. With an input of 120 V, the output becomes 120 V × 0.5 = 60 V. This is a step-down transformer, since the secondary has fewer turns than the primary, reducing the voltage. If you think about power, the current on the secondary would rise to roughly conserve power (ignoring losses), but the question asks for voltage, so the result is 60 V. The other voltages would require different turns relationships (for example, equal turns give 120 V, more turns on the secondary would give voltages above 120 V, and so on). The correct output is 60 V.

Voltage in a transformer is determined by the turns ratio between the primary and secondary windings. The secondary voltage equals the primary voltage times the secondary turns divided by the primary turns. Here, there are 1000 turns on the primary and 500 on the secondary, so the ratio Ns/Np is 500/1000 = 0.5. With an input of 120 V, the output becomes 120 V × 0.5 = 60 V. This is a step-down transformer, since the secondary has fewer turns than the primary, reducing the voltage. If you think about power, the current on the secondary would rise to roughly conserve power (ignoring losses), but the question asks for voltage, so the result is 60 V. The other voltages would require different turns relationships (for example, equal turns give 120 V, more turns on the secondary would give voltages above 120 V, and so on). The correct output is 60 V.