A null point is shown with compass needles indicated by arro

A \"null\" point is shown with compass needles indicated by arrows on each side of it. The tip of the arrow in each case corresponds to the N-pole (the pole that points north) of the compass needle. On the diagram, clearly indicate the direction of Earth\'s magnetic field using an labeled arrow. Explain your reasoning. Identify the points A and B on the bar magnet as N or S magnetic poles. Mark them as such on the diagram. Explain your reasoning. Calculate the magnetic \"pole\" strength of the bar magnet. Note the scale of the diagram

Solution

a) The neutral point shown in the diagram is on the equatorial line of the magnet where the magntic field due to bar magnet and Earth horizontel component will be cancelled. the geographical north and south polees are prallel to BA

On A side earth south pole and B side is earth north pole.

b) A is north pole and B is south pole

c) H= 2lm/4* pie* (d^2+l^2)^1.5

where H= 30 A/m , d= 0.15m , l=0.06m

m = 67.9 A-m