Question

A generator has a square coil consisting of 245 turns. The coil rotates at 84.5 rad/s in a 0.249-T magnetic field. The peak output of the generator is 65.7 V. What is the length of one side of the coil

Answer 1

0.141 m

Step-by-step explanation:

Using Faraday law for the magnetic generator, we have the following formula for the turning coil:

`V = NA(\Delta B)/(\Delta t)`

where V = 65.7 V is the output voltage, N = 245 is the number of turns, A is the coil area.
`\Delta B / \Delta t` is the rate of change in magnetic flux, which can be calculated if we know that time it takes to rotate π/2 rad so B changes from 0.249 to 0.

`(\Delta B)/(\Delta t) = (\Delta B)/((\pi/2)/(84.5)) = (0.249 - 0)/(0.0186) = 13.4 T/s`

Therefore:
`V = NA 13.4`

`65.7 = 245*13.4*A`

`A = 65.7 / (245*13.4) = 0.02 m^2`

Since this is a square coil, we can calculate the side length:

`s = √(A) = √(0.02) = 0.141 m`