A step down transformer is used to reduce the main supply of 220 V to 10 V . If the primary draws 5 A and secondary 88 A current, calculate the efficiency of the transformer.

Step-by-step solution

e_p=220 ~V , e_s=10 ~V , I_p=5 ~A and I_s=88 ~A Input power, P_i=e_P I_P=220 5=1100 ~W Output power, P_o=e_s I_s=10 88=880 ~W Efficiency, = P₀ P₁ = 880 1100 =0.8 or 80 %