In the given figure N-S is a compass needle. Look at this and show deflection of magnetic compass.

Deflection of magnetic compass is shown in the figure 

The magnetic compass deflects like in above figure.It the current is increased in the conductor the deflection of the compass needle increases. This is because the strength of magnetic field varies directly as the magnitude of the electric current, or the current passing through the wire.The deflection increases when the current is increased because the magnitude of the field is directly proportional to the strength of the electric current. That is, stronger the electric field, stronger the magnetic field.The difference, expressed in degrees, between the direction a magnetic compass needle points and true or astronomical north; magnetic declination is deflection in magnetic compass.

 A current carrying wire always produces a magnetic field around it and due to this magnetic field the needle of magnetic compass deflects.On changing the direction of flow of current, the direction of deflection of compass needle is reversed. ... This shows that the magnitude of the magnetic field produced by a given current in the wire is inversely proportional to the distance from the wire.