Electromotive force induced in rotating coil

Suppose a coil is being rotated around the axis that lies in the coil’s cross section (see Figure) in a magnetic field under the conditions described below. Then an electromotive will be induced in the contour of the coil. Its amplitude depends on the number of turns in the coil, the magnetic flux density, the angular frequency of the coil’s rotation and the area of the coil’s contour.

Notes:

  1. The angle \(\varphi\) between the normal to the coil’s contour and the magnetic flux density is \(\varphi \propto \cos(\omega t)\). See Figure.

Conditions:

  1. The magnetic field is uniform.

  2. The angular velocity of the coil’s rotation is orthogonal to the magnetic field.

  3. The area of the coil’s contour is constant.

  4. The angular speed of the coil’s rotation constant.

electromotive_force

electromotive_force induced in the coil.

Symbol:

E

Latex:

\(\mathcal{E}\)

Dimension:

voltage

coil_turn_count

Number of turns in the coil. See positive_number.

Symbol:

N

Latex:

\(N\)

Dimension:

dimensionless

magnetic_flux_density

magnetic_flux_density.

Symbol:

B

Latex:

\(B\)

Dimension:

magnetic_density

contour_area

Cross-sectional area of the contour enclosed by the coil.

Symbol:

A

Latex:

\(A\)

Dimension:

area

angular_frequency

angular_frequency of the coil’s rotation.

Symbol:

w

Latex:

\(\omega\)

Dimension:

angle/time

time

time.

Symbol:

t

Latex:

\(t\)

Dimension:

time

law

E = -N * B * A * w * sin(w * t)

Latex:
\[\mathcal{E} = - N B A \omega \sin{\left(\omega t \right)}\]