Question

Two generators use the same magnetic field and operate at the same frequency. Each has a single-turn circular coil. One generator has a coil radius of 5.1 cm and a peak emf of 1.8 V. The other generator has a peak emf of 3.9 V. Find the coil radius r of this other generator.

Answer 1

Answer:

The radius of the second coil will be 7.5 cm

Explanation:

We have given that radius of the first coil $r_1=5.1cm=0.051m$

Peak emf of the first generator $e_1=1.8Volt$

Peak emf of the second generator $e_2=3.9Volt$

We know that induced emf is rate of change of magnetic flux , that is equal to magnetic field multiply by change in area

So emf will be proportional to the change in area

So $\frac{e_1}{e_2}=\frac{A_1}{A_2}$

$\frac{1.8}{3.9}=\frac{0.051^2}{r_2^2}$

$r_2=0.075m = 7.5cm$

So the radius of the second coil will be 7.5 cm