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I found a problem with a compass and a magnet, as diagrammed below.

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The needle of the compass was oscillating in an uniform magnetic field, but when a soft iron bar was placed near the needle, then the needle came to rest after some time. Why did this occur?

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As the compass needle is magnetized, the oscillation of the needle creates a varying magnetic field in the nearby areas. Consequently, eddy currents are induced in the nearby soft iron bar due to the varying field, leading to energy loss and the eventual cessation of the oscillation

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At first , the N pole of compass was repelled by N pole of magnet when the compass needle is repelled South Pole of compass gets attracted this helps in gaining kinetic energy this needle once again points N pole towards the N pole of magnet When soft iron bar is placed it absorbs the magnetic field or in other words protect compass from getting interrupted by magnetic field of magnet and compass now comes to halt

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    $\begingroup$ Please add some Interpunction.Without it your text is not understandable. $\endgroup$
    – Thomas Fritsch
    Commented Jan 14, 2020 at 19:05
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The magnetic field of the earth is uniform over a room sized volume, and can cause only a torque on a compass needle (which will cause an oscillation if the needle is disturbed). The non-uniform field from a bar magnet will exert a net force on the needle (and a higher frequency of oscillation). This will increase the friction between the needle and its mount and cause a more rapid damping of the oscillations.

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