A 1.6-m wire is wound into a coil with a radius of 3.2cm.

-If this coil is rotated at 93 rpm in a (7.1x10^-2) - T magnetic field, what is it's maximum emf? (In 2 significant figures in mV)

18 mV

Explanation:

The maximum emf is:

ε = N B A ω

where N is the number of turns in the coil,

B is the strength of the magnetic field,

A is the area of the coil,

and ω is the angular velocity.

The number of turns N is equal to the length of the wire divided by the circumference of the coil.

N = L / (2πr)

Area of the coil is:

A = πr²

The angular velocity in rad/s is:

ω = rpm * 2π / 60 s

Therefore:

ε = (L / (2πr)) B (πr²) (rpm * 2π / 60 s)

ε = L B r (rpm * π / 60 s)

Plugging in values:

ε = (1.6 m) (0.071 T) (0.032 m) (93 * π / 60 s)

ε = 0.018 Tm²/s

ε = 18 mV