English

The water droplets are spherical in free fall due to ______ - Physics

Advertisements
Advertisements

Question

The water droplets are spherical in free fall due to ______ 

Options

  • gravity

  • intermolecular attraction

  • Surface tension

  • Viscosity

MCQ
Fill in the Blanks

Solution

The water droplets are spherical in free fall due to Surface tension.

shaalaa.com
  Is there an error in this question or solution?
Chapter 2: Mechanical Properties of fluids - MCQ’s

APPEARS IN

SCERT Maharashtra Physics [English] 12 Standard HSC
Chapter 2 Mechanical Properties of fluids
MCQ’s | Q 2

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Derive an expression for excess pressure inside a drop of liquid.


In which of the following substances, surface tension increases with increase in temperature ?

  1. Copper
  2. Molten copper
  3. Iron
  4. Molten iron

The surface tension of water at 0ºc is 75·5 dyne/cm. Find surface tension of water at 25°C. [ α for water = 0·0021/°C ]


Explain why The angle of contact of mercury with glass is obtuse, while that of water with glass is acute


The free surface of a liquid resting in an inertial frame is horizontal. Does the normal to the free surface pass through the centre of the earth? Think separately if the liquid is (a) at the equator (b) at a pole (c) somewhere else.


If a mosquito is dipped into water and released, it is not able to fly till it is dry again. Explain 


A heavy mass is attached to a thin wire and is whirled in a vertical circle. The wire is most likely to break


An ice cube is suspended in vacuum in a gravity free hall. As the ice melts it


Air is pushed into a soap bubble of radius r to double its radius. If the surface tension of the soap solution in S, the work done in the process is 


Which of the following graphs may represent the relation between the capillary rise hand the radius r of the capillary?


Water rises in a vertical capillary tube up to a length of 10 cm. If the tube is inclined at 45°, the length of water risen in the tube will be


A 20 cm long capillary tube is dipped in water. The water rises up to 8 cm. If the entire arrangement is put in a freely falling elevator, the length of water column in the capillary tube will be


The contact angle between a solid and a liquid is a property of

(a) the material of the solid
(b) the material of the liquid
(c) the shape of the solid
(d) the mass of the solid


When a capillary tube is dipped into a liquid, the liquid neither rises nor falls in the capillary.
(a) The surface tension of the liquid must be zero.
(b) The contact angle must be 90°.
(c) The surface tension may be zero.
(d) The contact angle may be 90°.


Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a soap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury, soap solution and water are 0.465 N m−1, 0.03 N m−1 and 0.076 N m−1 respectively.


Find the surface energy of water kept in a cylindrical vessel of radius 6.0 cm. Surface tension of water = 0.075 J m−2.


The lower end of a capillary tube of radius 1 mm is dipped vertically into mercury. (a) Find the depression of mercury column in the capillary. (b) If the length dipped inside is half the answer of part (a), find the angle made by the mercury surface at the end of the capillary with the vertical. Surface tension of mercury = 0.465 N m−1 and the contact angle of mercury with glass −135 °.


Solve the previous problem if the lead piece is fastened on the top surface of the block and the block is to float with its upper surface just dipping into water.


A cubical metal block of edge 12 cm floats in mercury with one fifth of the height inside the mercury. Water in it. Find the height of the water column to be poured.
Specific gravity of mercury = 13.6.


Why is the surface tension of paints and lubricating oils kept low?


Derive an expression for capillary rise for a liquid having a concave meniscus.


The surface tension of a liquid at critical temperature is ______ 


What will be the shape of the liquid meniscus for the obtuse angle of contact? 


Water rises to a height of 20 mm in a capillary tube. If the radius made 1/3rd of its previous value, to what height will the water now rise in the tube?  


Explain the phenomena of surface tension on the basis of molecular theory.


Obtain an expression for the capillary rise or fall using the forces method.  


How does the friction arise between the surfaces of two bodies in relative motion?


Describe an experiment to prove that friction depends on the nature of a surface.


How is surface tension related to surface energy?


What are the factors affecting the surface tension of a liquid?


A capillary of diameter d mm is dipped in water such that the water rises to a height of 30 mm. If the radius of the capillary is made `(2/3)` of its previous value, then compute the height up to which water will rise in the new capillary?


Why coffee runs up into a sugar lump (a small cube of sugar) when one corner of the sugar lump is held in the liquid?


The surface tension of the two liquids is respectively 20 and 60 dyne cm-1. The liquids drop from the ends of two tubes of the same radius. The ratio of the weights of the two drops is ______


If the surface tension of a soap solution is 3 × 10-2 N/m then the work done in forming a soap film of 20 cm × 5 cm will be ______.


A molecule of water on the surface experiences a net ______.


A water drop of radius R' splits into 'n' smaller drops, each of radius 'r'. The work done in the process is ______.

T = surface tension of water


The upward force of 105 dyne due to surface tension is balanced by the force due to the weight of the water column and 'h' is the height of water in the capillary. The inner circumference of the capillary is ______.

(surface tension of water = 7 × 10-2 N/m)


Soap solution is used for cleaning dirty clothes because ______.


What is surface tension? Explain the applications of surface tension.


The length of a needle floating on water is 2 cm. The additional force due to surface tension required to pull the needle out of water will be (S.T. of water = 7.0 × 10−2 N/m). 


The angle of contact at the interface of water-glass is 0°, Ethylalcohol-glass is 0°, Mercury-glass is 140° and Methyliodide-glass is 30°. A glass capillary is put in a trough containing one of these four liquids. It is observed that the meniscus is convex. The liquid in the trough is ______.


The sufrace tension and vapour pressure of water at 20°C is 7.28 × 10–2 Nm–1 and 2.33 × 103 Pa, respectively. What is the radius of the smallest spherical water droplet which can form without evaporating at 20°C?


This model of the atmosphere works for relatively small distances. Identify the underlying assumption that limits the model.


A soap bubble of radius 3 cm is formed inside another soap bubble of radius 6 cm. The radius of an equivalent soap bubble which has the same excess pressure as inside the smaller bubble with respect to the atmospheric pressure is ______ cm.


We have three identical perfectly black plates. The temperatures of first and third plate is T and 3T. What is the temperature of second plate if system is in equilibrium?


A drop of water and a soap bubble have the same radii. Surface tension of soap solution is half of that of water. The ratio of excess pressure inside the drop and bubble is ______.


A coaxial cylinder made of glass is immersed in liquid of surface tension ' S'. Radius of inner and outer surface of cylinder are R1 and R2 respectively. Height till which liquid will rise is (Density of liquid is p):


In a U-tube, the radii of two columns are respectively r1 and r2. When a liquid of density ρ(θ = 0°) is filled in it, a level difference of h is observed on two arms, then the surface tension of the liquid is ______.


When an air bubble of radius r rises from the bottom to the surface of a lake, its radius becomes `(5r)/4`. Taking the atmospheric pressure to be equal to the 10 m height of the water column, the depth of the lake would approximately be ______.

(ignore the surface tension and the effect of temperature)


In most liquids, with the rise in temperature, the surface tension of a liquid ______.


Find the work done when a drop of mercury of radius 2 mm breaks into 8 equal droplets. [Surface tension of mercury = 0.4855 J/m2].


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×