Question

The slope of the I-V curve is 87°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

(a) 0.0524 Ω

(b) 0.0254 Ω

(c) 0.0543 Ω

(d) 0.0648 Ω

I have been asked this question in an international level competition.

This intriguing question originated from DC Motors in chapter Characteristics of DC & AC Motors of Electric Drives

Answer 1

Right option is (a) 0.0524 Ω

Easy explanation: The slope of the I-V curve is reciprocal of resistance. The slope given is 87° so R=1÷tan(87°)=.0524 Ω.