Question

7. A4:1 voltage step up transformer has 150 volt across the primary and 600 ohm resistance across
the secondary. Assuming 100% efficiency, the primary current equals.
(a) 1/4 A
(b) 400 mA
(C) 4A
(d) 1A​

Answer 1

Explanation:

This is from sample college test. I disagree this answer but agree with the all the other problems answers.

I see the problem as the load across the secondary being 600 ohms.

The secondary voltage would be 600V and current 1 A.

And the circuit in the primary being 5 Amps, answer B.

Q.33 A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance

across the secondary. Assuming 100% efficiency, the primary current equals

(A) 0.2 Amp. (B) 5 Amps.

© 10 Amps. (D) 20 Amps.

Ans: A

I1= V1 /R1 = 120/600 = 0.2 (n = 100%, losses are zero \V1 = VR = I1R1)

Answer 2

Answer(c) 4A

Explanation: