What does a transformer do to electrical currents?

What does a transformer do to electrical currents?

• A. Changes the voltage
• B. Increases current
• C. Stores energy
• D. Reduces resistance

Answer: (A)

Transformers work by electromagnetic induction to transfer AC power between windings and primarily change the voltage level according to the turns ratio. The voltage ratio follows Vp/Vs = Np/Ns. Because power is roughly conserved (Vp Ip ≈ Vs Is), the currents adjust inversely with that voltage change: if the voltage is stepped up, the current on the secondary drops for a given load, and if the voltage is stepped down, the current increases. So the device changes currents indirectly by altering voltage, rather than storing energy or inherently reducing resistance. Any apparent impedance change on one side is the reflected load scaled by the turns ratio, not a property of the winding’s resistance itself.

Transformers work by electromagnetic induction to transfer AC power between windings and primarily change the voltage level according to the turns ratio. The voltage ratio follows Vp/Vs = Np/Ns. Because power is roughly conserved (Vp Ip ≈ Vs Is), the currents adjust inversely with that voltage change: if the voltage is stepped up, the current on the secondary drops for a given load, and if the voltage is stepped down, the current increases. So the device changes currents indirectly by altering voltage, rather than storing energy or inherently reducing resistance. Any apparent impedance change on one side is the reflected load scaled by the turns ratio, not a property of the winding’s resistance itself.