Question

An ideal transformer has 500 rums in the primary and 2500 in the secondary. The meters of the secondary are indicating 200 V, 8 A, under these conditions. What would the meters of the primary read?

• A. 100 V, 16 A
• B. 40 V, 40 A
• C. 160 V, 10 A
• D. 80 V, 20 A

Answer 1

Answer: (B)

Given, $N_p=500$ turns, $N_s=2500,I_s=8A$ , $e_s=200volt$ Transformation ratio $(k)=\frac{N_s}{N_p}=\frac{e_s}{e_p}=\frac{I_p}{I_s}$ $\therefore$ $\frac{N_s}{N_p}=\frac{e_s}{e_p}\frac{2500}{500}=\frac{200}{e_p}$ $\therefore$ $e_p=40volt$ Again, $\frac{N_s}{N_p}=\frac{I_p}{I_s}$ $\frac{2500}{500}=\frac{I_p}{8}$ $I_p=40A$