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Electromagnetism Formula

What is Transformer Law?

An ideal transformer steps voltage up or down in proportion to the ratio of coil turns.

Formula: \frac{V_p}{V_s} = \frac{N_p}{N_s}

Plain-English Meaning

An ideal transformer steps voltage up or down in proportion to the ratio of coil turns.

Keep charge, field, potential, and current distinct. That single habit fixes a large fraction of electromagnetism errors.

Deeper Explanation

An ideal transformer steps voltage up or down in proportion to the ratio of coil turns.

Worked Example

Problem: A transformer has N_p = 500 turns and N_s = 100 turns. Input voltage is 240 V. Find V_s.

  • V_s = V_p × N_s/N_p = 240 × 100/500 = 240 × 0.2 = 48 V

Result: V_s = 48 V

At A Glance

Category: Electromagnetism

Levels covered:

Best use: Start with the formula meaning, then move to the worked example and quiz so the equation turns into a tool instead of a memorised line.