Water rises to a height h in a capillary tube of area of cross-section a. To what height will water rise in a capillary tube of area of cross-section 4a?


Correct option is


Area of cross-section . In terms of a, the height to which a liquid rises in a capillary tube, is given by



Thus, h is inversely proportional to . If a is increased 4 times, h will decrease by a factor of 2.



A rectangular tank is filled to the brim with water. When a hole at its bottom is unplugged, the tank is emptied in time T. If the tank is half-filled with water, it will be emptied in time


Two capillary tubes A and B of radii ra and rb and lengths la and lbrespectively are held horizontally. The volume of water flowing per second through tube A is Qa when the pressure difference across its ends is maintained at P. When the same pressure difference is maintained across tube B, the volume of water flowing per second through it is Qb. The ratio  is 


. If a pressure difference P is maintained across tube A, the rate of flow of water in it is Q. If the tubes are connected in series and the same pressure difference P is maintained across the combination, the rate of flow through the combination will be


If the surface tension of soap solution is , What is the work done in blowing soap bubble of radius r?


The work done to break up a drop of a liquid of radius R and surface tension  into eight drops, all of the same size, is 


A soap bubble of radius r is blown up to form a bubble of radius 2r under isothermal conditions. If  is the surface tension of soap solution, the energy spent in doing so is  


If the air bubble is formed at a depth h inside the container of soap solution of density , the total pressure inside the bubble is (here P0denotes the atmospheric pressure) 


A small drop of water of surface tension  is squeezed between two clean glass plates so that a thin layer of thickness d and area A is formed between them. If the angle of contact is zero, the force required to pull the plates apart is 


Eight drop of water, each of radius r, coalesce to form a single big drop. The energy released is used up in raising the temperature of the big drop. If is the surface tension of water and  its density and J the mechanical equivalent of heat (all expressed in SI units), the rise in the temperature of the drop is 


A metal sphere of volume V, having a cavity inside it, floats on water completely submerged. If the relative density of the metal is 1.5, the volume of the cavity is