On Fig. 10.1, draw the magnetic field pattern inside, above and below the solenoid.
A second solenoid Y is joined to a sensitive centre-zero ammeter. Solenoid Y is situated in the magnetic field of X. As the resistance of the variable resistor is gradually reduced, the pointer on the sensitive ammeter moves slightly to one side. Explain why this happens.
The switch S is now opened. Describe and explain what occurs to the ammeter deflection while the switch is being opened.
Fig. 10.2 shows a transformer made of two coils wound on an iron core. The transformer is linked to an electricity transmission cable. Explain the purpose of the iron core in the transformer.
The transformer delivers electrical power to a factory at 33 000 V. The current supplied is 85 A. Calculate the electrical power received by the factory.
Calculate the electrical energy received by the factory in 1.0 hour.