What happens to the transformer’s power when the voltage is reduced?

What happens to the transformer’s power when the voltage is reduced?

• A. It increases
• B. It remains the same
• C. It decreases proportionally
• D. It doubles

Answer: (B)

When the voltage is reduced in a power transformer, the power remains the same provided that the load does not change. This is because transformers operate based on the principle of conservation of energy. The input power (which is the product of voltage and current on the primary side) must equal the output power (the product of voltage and current on the secondary side) minus any losses. Assuming an ideal transformer with no losses, the relation between the primary and secondary voltages and currents is given by the formula: Power (P) = Voltage (V) × Current (I). If the voltage is reduced on the output side, the current must increase to maintain the same power output. Therefore, the overall power drawn from the transformer does not change as long as the load remains constant. This illustrates that while the voltage may change, the actual power flowing through the transformer under steady-state conditions remains constant, confirming that it does indeed remain the same. This principle ensures effective energy transfer in electrical systems, and understanding it is crucial for system operators when managing load and distribution efficiently.

When the voltage is reduced in a power transformer, the power remains the same provided that the load does not change. This is because transformers operate based on the principle of conservation of energy. The input power (which is the product of voltage and current on the primary side) must equal the output power (the product of voltage and current on the secondary side) minus any losses.

Assuming an ideal transformer with no losses, the relation between the primary and secondary voltages and currents is given by the formula:

Power (P) = Voltage (V) × Current (I).

If the voltage is reduced on the output side, the current must increase to maintain the same power output. Therefore, the overall power drawn from the transformer does not change as long as the load remains constant. This illustrates that while the voltage may change, the actual power flowing through the transformer under steady-state conditions remains constant, confirming that it does indeed remain the same.

This principle ensures effective energy transfer in electrical systems, and understanding it is crucial for system operators when managing load and distribution efficiently.