Question

Identify the relation between charge flow and change in magnetic flux.

(a) ∆Q = ∆ΦB×r

(b) ∆Q = 2∆Φ;B r

(c) ∆Q = \(\frac {\triangle \Phi_B}{r}\)

(d) ∆Q = \(\frac {\triangle \Phi_B}{2r}\)

I have been asked this question during an online interview.

The above asked question is from Energy Consideration: A Quantitative Study topic in division Electromagnetic Induction of Physics – Class 12

Answer 1

Right choice is (c) ∆Q = \(\frac {\triangle \Phi_B}{r}\)

Easy explanation: There is a relationship between the charge flow through the circuit and the change in the magnetic flux. According to Faraday’s Law, the induced emf is given by:

|ε|=\( \frac {\triangle \Phi_B}{\triangle t}\)

But, |ε|=Ir=\(( \frac {\triangle Q}{\triangle t} ) \)r

Therefore, the relation is given by:

∆Q = \(\frac {\triangle \Phi_B}{r}\)