Magnetic fields

Question 1

What is the function of the core of a transformer?

Answer 1

Increases linkage of magnetic flux

Question 2

What is the function of the secondary coil in a transformer?

Answer 2

Has a varying magnetic flux passing through it, which induces an emf that is determined by the number of turns.

Question 3

Explain how the efficiency of a transformer is increased by constructing the core out of thin iron sheets.

Answer 3

The sheets of laminations are made from insulator/ high resistivity material. This reduces eddy currents/ charge flowing in the core, which means that smaller emfs are induced in the core.

Question 4

Why shouldn’t the voltage in a long-distance transmission be too low?

Answer 4

If the voltage is too low then power is transmitted at a high current = energy loss due to heating.

Question 5

Why shouldn’t the voltage in a long-distance transmission be too high?

Answer 5

If the voltage is too high, it creates major insulation/ isolation difficulties.