Question

Pick out the dimensional formula of emf from the following.

(a) [M^1L^2T^3A^1]

(b) [ML^3T^3A^1]

(c) [M^2L^2T^1A^-1]

(d) [ML^2T^-3A^-1]

I had been asked this question in final exam.

Enquiry is from Current Electricity in section Current Electricity of Physics – Class 12

Answer 1

The correct answer is (d) [ML^2T^-3A^-1]

The best I can explain: Electromotive force (emf) is defined as the potential difference between the two terminals of a cell in an open circuit. The SI unit of emf is \(\frac {joule}{coulomb}\) or volt. So, its dimensional formula is [ML^2T^-3A^-1].