A magnetic needle is placed on a cork floating on a lake in the northern hemisphere. Does this needle together with the cork move towards the north of the lake?

An iron needle slowly placed on the surface of water floats in it because :

Why does a needle float on clear water, but sinks when some detergent is added to water?

Give the magnitude and direction of the net force acting onfa) a drop of rain falling down with a constant speed. (b) a cork of mass 10 g floating on water. (c) a kite skillfully held stationary in the sky. (cf) a car moving with a constant velocity of 30 km/h on a rough road.

Write the Oersted's investigation on deflection of a magnetic compass needle when placed nearby a long straight current carrying conductor.