electromagnetic induction

Question 1

when is a voltage induced in a conductor or coil

Answer 1

when it moves through a magnetic field or when the magnetic field around it changes. This is called electromagnetic induction

Question 2

size of voltage in a conductor or coil depends on (3)

Answer 2

how fast the conductor moves, how strong the magnetic field is, and how many coils of wire there are.

Question 3

how is electricity generated by rotation

Answer 3

is generated when a magnet rotates inside a coil of wire, or when a coil rotates within a magnetic field. This movement changes the magnetic field through the coil, which induces a voltage.

Question 4

structure of transformer

Answer 4

AC current flows into the primary coil.

This creates a changing magnetic field in the iron core.

The changing magnetic field passes through the iron core to the secondary coil.

This induces a voltage in the secondary coil (because of electromagnetic induction).

The output voltage depends on the number of turns in each coil.

Question 5

step up transformer

Answer 5

when electricity is transmitted over large distances, the current in the wires heats them up, resulting in energy loss

this electrical energy is transferred at high voltages from power stations

its then transferred at lower voltages in each locality for domestic use

Question 6

what does a step up transformer do

Answer 6

increases the potential difference of a power source

Question 7

step up transformers are placed

Answer 7

after a power station

Question 8

step down transformer

Answer 8

is for domestic use (reduce the voltage to safe levels for use in appliances and devices).

Question 9

step down transformers are

Answer 9

placed before buildings