In an experiment to verify Stokes law, a small spherical ball of radius r and density $$\rho $$ falls under gravity through a distance h in air before entering a tank of water. If the terminal velocity of the ball inside water is same as its velocity just before entering the water surface, then the value of h is proportional to :
(ignore viscosity of air)

Two coherent sources of sound, S₁ and S₂, produce sound waves of the same wavelength, $$\lambda $$ = 1 m, in phase. S₁ and S₂ are placed 1.5 m apart (see fig). A listener, located at L, directly in front of S₂ finds that the intensity is at a minimum
when he is 2 m away from S₂. The listener moves away from S₁, keeping his distance from S₂ fixed. The adjacent maximum of intensity is observed when the listener is at a distance d from S₁. Then, d is :

The velocity (v) and time (t) graph of a body in a straight line motion is shown in the figure. The point S is at 4.333 seconds. The total distance covered by the body in 6 s is :

A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of 6 mA it produces a deflection of 2^o, its figure of merit is close to :