you are given two similar barone of which is magnet what else would you requireto test which one is magnet
Answers
Let us see what happens when we bring a bar which is not magnetised (shown in golden colour) closer to one which is magnetised (Shown in gray).
In a bar magnet, the intensity of the magnetic field is strongest at the two ends (poles) and weakest at the central region. So the bar which is not magnetised experiences strong force of attraction near the ends of the bar magnet but no force at the centre. See the diagram on the left.
However when we bring a bar magnet closer to the bar that is not magnetised, the force of attraction is same everywhere. See the diagram on the right.
The facts illustrated above can be used to determine which one of the two is a magnet without using anything other than the the two bars.
So you have two similar bars A and B, one of which is magnetised and the other is not. To see which one of the two is magnet, pick up one (say A) and lower one of its ends, first on one of the ends of the other (say B) and then on the middle of B. If you notice that at the end of B, A experience a force but no force in the middle of the B then B is magnetised. If you do not notice any change from the end to the middle of B then A is magnetised.