Question

(i) Draw a step-up transformer diagram. Describe its working principle. Explain 3 energy loss causes.
(ii) Does a step-up transformer violate energy conservation? Explain.
(iii) A step-up transformer (N_p=200, N_s=3000) has V_p=90V, I_s=2A. Calculate V_s and I_p.

Hint:

Transformer operation and energy conservation

Answer 1

(i) The diagram must depict the primary coil, secondary coil, and the iron core. The underlying principle is electromagnetic induction. Potential losses include copper losses, iron losses (resulting from eddy currents and hysteresis), and flux leakage. (ii) Ideally, the input power should equal the output power. (iii) The ratio of secondary voltage to primary voltage equals the ratio of secondary turns to primary turns: \(V_s/V_p = N_s/N_p\). Consequently, the product of primary voltage and primary current equals the product of secondary voltage and secondary current: \(V_p*I_p = V_s *I_s\).