**Question: What happens when a 60 Hz transformer is operated on 50 Hz?**

Answer: The peak flux and magnetization current of a 60 Hz transformer increase when operated on 50 Hz supply.

**Explanation**

The flux in a transformer is defined as the ratio of voltage to frequency.

Mathematically,

**Ø _{max} = [V_{max} / f ] * k**

Where k is a constant.

Let’s assume the applied voltage is 120 V and f = 60 Hz.

**Ø _{max} = [120 V / 60 Hz ] = 2 … 1**

The decrease in frequency increases the flux:

**Ø _{max} = [120 V / 50 Hz ] = 2.4 … 2**

A decrease of 10 Hz frequency increase the flux by 20%.

For keeping same flux the transformer should be operated at 20% lower voltage.