Question

A 200V/120V step-down transformer of 90% efficiency is connected to an induction stove of resistance 40 Ω. Find the current drawn by the primary of the transformer.

Answer 1

Primary voltage, V_p = 200 V 

Secondary voltage, V_s = 120 V 

Efficiency, η = 90% 

Secondary resistance, R = 40 Ω 

Current drawn by the primary of the transformc,

l_p = \(\frac{V_s}{R_s}\) x l_s

Output power =V_s l_s