Question

In a transformer, the number of turns of primary coil and secondary coil are 5 and 4, respectively. If 220 V is applied on the primary coil, then the ratio of primary current to the secondary current is 

(1) 4 : 5 

(2) 5 : 4 

(3) 5 : 9 

(4) 9 : 5

Answer 1

Number of turns of primary coil, N_P=5; number of turns of secondary coil, N_S=4. Let the primary current be I_p and the secondary current be l_s. The ratio of primary current to the secondary current is obtained as follows:

Hence, the correct option is (1).