No two magnetic field lines can intersect each other. Explain.

Name three colours used and names of the wires used in household wiring.

Define magnetic field. Describe an activity to draw magnetic field lines around a bar magnet from one pole to another pole.

What is the shape of the magnetic field lines inside a solenoid?

How does a current-carrying solenoid behave?

$A$ uniform magnetic field is directed vertically upwards. In which direction should an $\alpha$-particle (which is a positively charged particle) be projected in this field so that it is deflected southwards? Name and state the rule used to find the direction in this case.