State the meaning of current.
State the magnitude of the electromotive force (e.m.f.) of the battery.
Calculate the resistance of the complete series circuit.
The voltmeter reads $6.5\,\text{V}$. Calculate the power dissipated in the solenoid.
The solenoid is made of copper and the student observes that, as time goes on, the solenoid becomes very hot. State and explain the effect of this rise in temperature on the ammeter reading.
The current in the solenoid magnetises the iron core so that the lower end of the core is an N-pole. On Fig. 9.1, draw the pattern and show the direction of the magnetic field in the region around the iron core.
Explain why the iron cylinder does not drop.
The switch S is opened. State and explain whether the iron cylinder stays in contact with the iron core.