# Physics 11 Practice Test

 Practice Test-Physics-XI Mechanics Of Solids  and fluids Time: 1 hour Max Marks:30
 Marks 1. A bottle full of a liquid is fitted with a tight cork. Explain why a slight blow on the cork may be sufficient to break the bottle. 2 2. Two vessels have the same base area but different shapes. The first vessel takes twice the volume of water that the second vessel requires to fill up a particular common height. Is the force exerted by water on the base of the vessel the same in the two cases? If so,why do vessel filled with water to that same height give different readings on a weighing machine? 2 3. A balloon filled with helium does not rise in air indefinitely but halts after a certain height. 2 4. The force required by a man to move his limbs immersed in water is similar than the force the same movement in air. 2 5. Water is depressed in a glass tube whose inner surface is coated with paraffin wax. Why? 2 6. Explain why water can be poured into a bottle with a narrow neck with the aid of glass tube? 2 7. Calculated the energy evolved when 8 droplets of water (surface tension 0.72 Nm-1) of radius mm each combine into one. 2 8. Find the work done in blowing a soap bubble of surface tension 0.06 Nm-1 from 2 cm radius to 5 cm radius. 2 9. Find the excess of pressure (i) inside a liquid drop (ii) inside a liquid bubble (iii) inside a bubble in a liquid. 3 10. What do you understand by angle of contact? On what factors does it depend? Where is the angle of contact obtuse, acute or zero degree. 3 11. A piece of ice is floating in a vessel containing water and inside the ice is bubble of air. What will be the effect on the level of water, when the ice melts? 1 12. A piece of ice is floating in a vessel containing water. What will be the effect on the level of water in jar, when ice melts and the temperature of water falls from 40c to 10C. 1 13. A body is just floating in a liquid (their densities are equal). What will happen to the body if it is slightly pressed and released? 1 14. A beaker containing a liquid is kept inside a big closed jar. It the air inside the jar is continuously pumped out. What will be the pressure in the liquid near the bottom of the liquid. 1 15. Why is the dam of water reservoir thick at the bottom? 1 16. Show that atmosphere exerts pressure and describe Torricelli’s experiment to study the atmospheric pressure. 3