Chapter 25: Electromagnetic Induction

Question 1

Describe electromagnetic induction.

Answer 1

The phenomenon of inducing voltage by changing the magnetic field in a coil of wire. Voltage is induced by the relative motion between a wire and a magnetic field. This is done whether the magnetic field of a magnet moves near a stationary conductor or the conductor moves in a stationary magnetic field.

Question 2

Describe Faraday’s Law.

Answer 2

The induced voltage in a coil is proportional to the product of the number of loops and the rate at which the magnetic field changes within those loops.

Question 3

Describe generator action.

Answer 3

Current-carrying conductor in a stationary magnetic field with relative motion between the two.

Question 4

What is a transformer?

Answer 4

The transfer of electrical energy through air between a primary set of coils to a secondary set of coils. The voltage can be stepped-up or stepped-down depending on the number of coils each set has.

Question 5

State the transformer equations (three).

Answer 5

Vpri/Npri = Vsec/Nsec
Pin = Pout
Vpri x Ipri = Vsec x Isec

V = voltage
N = number of turns
P = power
I = current