An object of the weight 80Kg on earth is taken to a planet where the acceleration due to gravity is one third of its value on earth. The weight of the object on that planet is

A negative charge and a positive potential 

A negative charge and a negative potential

A positively charged rod X is brought near an uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that Y has 

The principle of operation of an induction coil is based on

According to Newton's law of cooling, the heat energy lost per unit area of a body depends on the 

I. Surface area
II. Nature of the surface
III. Temperature of the surface
IV. Excess temperature over the surroundings

Physics