Electromagnetic induction and transformers

Question 1 of 10

Explain why electrical power is transmitted at high voltage. A power station sends 100 kW through cables of total resistance 5 Ω. Compare the power loss when transmitted at (a) 1,000 V, (b) 20,000 V.

Question 2 of 10

The direction of an induced current is given by

Question 3 of 10

A transformer with 200 primary turns steps 240 V down to 48 V. The number of secondary turns is ___.

Question 4 of 10

A transformer with 1000 primary turns steps 240 V down to 120 V. The number of secondary turns is ___.

Question 5 of 10

A transformer has 500 primary turns and 100 secondary turns. If the primary voltage is 11,000 V, find the secondary voltage.

Question 6 of 10

Describe the structure and action of a simple a.c. generator. Sketch the output voltage against time.

Question 7 of 10

A generator (dynamo) converts

Question 8 of 10

A stationary magnet inside a coil induces a steady current.

Question 9 of 10

Describe a simple experiment to demonstrate electromagnetic induction and state three factors that affect the size of the induced e.m.f.

Question 10 of 10

In an ideal transformer, power input equals power output.