what is an electromagnet? how can we determine north and south pole of an electromagnet with the help of magnetised iron bar.
Take the bar magnet near one pole of the electromagnet by holding it with an insulator and check if it attracts or repels the electromagnet. Repeat the process and hence determine the polarity of the electromagnet. Answer : An electromagnet is a piece of temporary magnet formed by passing electricity through coils which are wrapped around a core.The core is generally magnetic. The north and south pole of an electromagnet can be determined using a magnetised iron bar.A magnetised iron bar behaves like a bar magnet. Suspend it freely with a thread such that the thread is neaty wound at its centre.Note the alignment of the magnetised iron bar when it comes to rest.The north pole will be in the direction of magnetic north pole of earth.Reverse is the case for the south pole. Now ,similar poles repel each other and opposite poles attract each other.Take the magnetised iron bar near one pole of electromagnet.Check if it attracts or repels. Repeat the process. In this way the polarity of the electromagnet can be determined