Traditionally,which coloured insulation on wire is used for earthing?

Mention the angle between a current-carrying conductor and a magnetic field for which the force experienced by this conductor is maximum. (in $^{\circ}$)

Find the minimum rating of fuse that can be safely used on a line on which two $1.1 \, kW$ electric geysers are to run simultaneously. The supply voltage is $220 \, V$. (in $A$)

$(a)$ Describe an activity to draw a magnetic field line outside a bar magnet from one pole to another.
$(b)$ List any two properties of magnetic field lines.

How is alternating current $(AC)$ different from direct current $(DC)$?

The figure below shows a current-carrying loop passing through a sheet of cardboard. Draw three magnetic field lines on the cardboard.
Give two factors on which the magnitude of the magnetic field at the centre of the loop depends.