The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerin becomes constant after some time. If the density of glycerin is $${d \over 2}$$, then the viscous force acting on the ball will be :

A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in Water. The mass of water that will rise in this tube is :

A wire of length L, are of cross section A is hanging from a fixed support. The length of the wire changed to L₁ when mass M is suspended from its free end. The expression for Young's modulus is :

A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in tmperature. The length of aluminium rod is : ($$\alpha $$_Cu = 1.7 × 10^–5 K^–1 and $$\alpha $$_Al = 2.2 × 10^–5 K^–1)