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 

Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

SPEAK TO COUNSELLOR ? CLICK HERE

Question

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 

Solution

Correct option is

 

The energy released in the process is  joules, since R = 2r. Therefore, heat energy produced is  

           

  

                              

                              

If  is the rise in temperature, then we have 

         

.

SIMILAR QUESTIONS

Q1

A cylindrical jar has radius r. To what height h should it be filled with a liquid so that the force exerted by the liquid on the sides of the jar equals the force exerted on the bottom?

Q2

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

Q3

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 

Q4

. 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

Q5

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

Q6

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 

Q7

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  

Q8

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) 

Q9

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 

Q10

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?