Question

The slope of the V-I curve is 6.9°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

(a) .38 Ω

(b) .59 Ω

(c) .34 Ω

(d) .12 Ω

The question was posed to me in exam.

My question is from Methods to Reduce the Energy Loss During Starting topic in section Starting of Electric Drives

Answer 1

Right choice is (d) .12 Ω

To explain: The slope of the V-I curve is resistance. The slope given is 6.9° so R=tan(6.9°)=.12 Ω. The slope of the I-V curve is reciprocal of resistance.