An ideal transformer has 500 primary turns and 100 secondary turns. The primary voltage is 220 V AC. Calculate secondary voltage.

Solution & explanation

1. Given: Nₚ = 500; Nₛ = 100; Vₚ = 220 V.

2. For an ideal transformer supplied with AC, voltage ratio equals turns ratio.

   $$\frac{V_s}{V_p}=\frac{N_s}{N_p}$$

3. Multiply both sides by the primary voltage.

   $$V_s=\frac{N_s\times V_p}{N_p}$$

4. Insert the given values.

   $$V_s=\frac{22000}{500}$$

5. Multiply first, then divide.

   $$V_s=\frac{22000}{500}=44$$

6. This is a step-down transformer because the secondary has fewer turns.

7. State the result with units: Vₛ = 44 V.

Vₛ = 44 V