“Sir, is it true that in magnetic hill in Ladhak defies gravity? If so, Why?”
The “magnetic hill” is located on the Leh-Kargil-Batalik national highway, about 30 km from Leh, at a height of 14,000 feet above sea level. On its eastern side, flows the Indus, which originates in Tibet and goes to Pakistan. The Indian Army maintains a sikh Gurudwara near the hill where Guru Nanak Dev, meditated in the 17th century. Due to both the Gurudwara and the gravity hill, the area has become a popular sightseeing destination.
The hill is alleged to have magnetic properties strong enough to pull cars uphill and force passing aircraft to increase their altitude in order to escape magnetic interference; in reality, the effect is an optical illusion created by the gravity hill.
The slope of gravity hills is an optical illusion, although sites are often accompanied by claims that magnetic or even supernatural forces are at work.
The most important factor contributing to the illusion is a completely or mostly obstructed horizon; without a horizon, judging the slope of a surface is difficult as a reliable reference is missing. Objects one would normally assume to be more-or-less perpendicular to the ground (such as trees) may actually be leaning, offsetting the visual reference. The illusion is similar to the well-known Ames room, in which balls can also appear to roll against gravity.