Magnetic field lines are shown in the given diagram. $A$ student makes a statement that the magnetic field at $X$ is stronger than at $Y$. Justify this statement. Also,redraw the diagram and mark the direction of magnetic field lines.

Draw a diagram to show how a magnetic needle deflects when it is placed above or below a straight conductor carrying current,depending on the direction of the current in the conductor.

What colour wire is used for earthing or grounding?

Explain the meanings of the words "electromagnetic" and "induction" in the term electromagnetic induction. List three factors on which the value of induced current produced in a circuit depends. Name and state the rule used to determine the direction of induced current. State one practical application of this phenomenon in everyday life.

Draw the pattern of magnetic field lines associated with a current-carrying straight conductor. State how the magnetic field produced changes:
$(i)$ with an increase in current in the conductor,and
$(ii)$ with an increase in the distance from the conductor.

In the below figure,$A$ and $B$ represent two straight wires carrying equal currents in a direction at right angles to the plane of paper inwards. Sketch separately the magnetic field lines produced by each current. Give a reason why the magnetic field at $K$ (mid-point of the line joining $A$ and $B$) will be zero.
What will be the effect on the magnetic field at $K$ if the current in wire $B$ is reversed?