In the northern hemisphere, if an aircraft is accelerated or decelerated, the magnetic compass will normally indicate

a turn in the NORTH

Explanation:

As , the aircraft is decelerated or accelerated , then the magnetic compass will indicate a turn towards the NORTH direction .

As , In the region of Northern Hemisphere , as acceleration (east or west) develops a turn towards the North direction . But considering in the region of  Southern Hemisphere effects are exactly the reverse i.e. acceleration produces an apparent turn towards the South direction .