In step-down transformer, the AC output gives the

The correct answer is current more than the input current.

Key Points

• A Transformer is a static apparatus, with no moving parts, which transforms electrical power from one circuit to another with changes in voltage and current and no change in frequency.
• There are two types of transformers classified by their function: Step up Transformer and Stepdown Transformer.
• A Step-up Transformer is a device that converts the low primary voltage to a high secondary voltage i.e. it steps up the input voltage.
• A Step-down Transformer, on the other hand, steps down the input voltage i.e. the secondary voltage is less than the primary voltage.
• Current and Voltage Relation in Step Down Transformer
• We will now see how this works. Let V_P be the voltage at the primary, I_P be the current at the primary and P_P be the power at the primary side of the transformer.
• We know that the power can be calculated by simply multiplying the voltage and current. Hence, the power at the primary side of the transformer is given by
• P_P = V_P * I_P
• Similarly, let V_S be the voltage at the secondary, I_S be the current at the secondary, and P_S be the power at the secondary side of the transformer.
• The power at the secondary of the transformer is given by
• P_S = V_S * I_S
• Since, the power in a transformer is constant, P_P = P_S.
• Which means, V_P * I_P = V_S * I_S
• As V_S is less than V_P in a step-down transformer, I_S has to be more than I_P.
• Hence, the output voltage in a step-down transformer is less than that of the primary voltage and the output current is more than the input current. Hence, Option 1 is correct.

Image of Step-Down Transformer: