A wooden stick 2m long is floating on the surface of water. The surface tension of water 0.07 N/m. By putting soap solution on one side of the sticks the surface tension is reduced to 0.06 N/m. The net force on the stick will be

(a) 0.07 N                                (b) 0.06 N
(c) 0.01 N                                (d) 0.02 N

Concept Questions :-

Surface tension
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Difficulty Level:

The force required to take away a flat circular plate of radius 2 cm from the surface of water, will be (the surface tension of water is 70 dyne/cm)

(a)                       (b)

(c)                        (d)

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Surface tension may be defined as

(a) The work done per unit area in increasing the surface area of a liquid under isothermal condition

(b) The work done per unit area in increasing the surface area of a liquid under adiabatic condition

(c) The work done per unit area in increasing the surface area of a liquid under both isothermal and adiabatic conditions

(d) Free surface energy per unit volume

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Energy needed in breaking a drop of radius R into n drops of radii r is given by

(a) $4\mathrm{\pi T}\left({\mathrm{nr}}^{2}-{\mathrm{R}}^{2}\right)$                        (b) $\frac{4}{3}\mathrm{\pi }\left({\mathrm{r}}^{3}\mathrm{n}-{\mathrm{R}}^{2}\right)$

(c) $4\mathrm{\pi T}\left({\mathrm{R}}^{2}-{\mathrm{nr}}^{2}\right)$                         (d) $4\mathrm{\pi T}\left({\mathrm{r}}^{2}\mathrm{n}+{\mathrm{R}}^{2}\right)$

Concept Questions :-

Surface tension
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Difficulty Level:

The potential energy of a molecule on the surface of liquid compared to one inside the liquid is  -
(a) Zero                                             (b) Smaller
(c) The same                                      (d) Greater

Concept Questions :-

Surface tension
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Difficulty Level:

Two droplets merge with each other and forms a large droplet. In this process

(a) Energy is liberated

(b) Energy is absorbed

(c) Neither liberated nor absorbed

(d) Some mass is converted into energy

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Radius of a soap bubble is 'r', surface tension of soap solution is T. Then without increasing the temperature, how much energy will be needed to double its radius

(a) $4{\mathrm{\pi r}}^{2}\mathrm{T}$                        (b) $2{\mathrm{\pi r}}^{2}\mathrm{T}$

(c) $12{\mathrm{\pi r}}^{2}\mathrm{T}$                       (d) $24{\mathrm{\pi r}}^{2}\mathrm{T}$

Concept Questions :-

Surface tension
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Difficulty Level:

Work done in splitting a drop of water of 1 mm radius into ${10}^{6}$ droplets is (Surface tension of water )

(a)                   (b)

(c)                    (d)

Concept Questions :-

Surface tension
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The amount of work done in blowing a soap bubble such that its diameter increases from d to D is (T= surface tension of the solution)

(a) $4\mathrm{\pi }\left({\mathrm{D}}^{2}-{\mathrm{d}}^{2}\right)\mathrm{T}$                     (b) $8\mathrm{\pi }\left({\mathrm{D}}^{2}-{\mathrm{d}}^{2}\right)\mathrm{T}$

(c) $\mathrm{\pi }\left({\mathrm{D}}^{2}-{\mathrm{d}}^{2}\right)\mathrm{T}$                        (d) $2\mathrm{\pi }\left({\mathrm{D}}^{2}-{\mathrm{d}}^{2}\right)\mathrm{T}$

Concept Questions :-

Surface tension
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Difficulty Level:

A spherical drop of oil of radius 1 cm is broken into 1000 droplets of equal radii. If the surface tension of oil is 50 dynes/cm, the work done is

(a) 18 $\pi$ ergs                     (b) 180 $\pi$ ergs
(c) 1800 $\pi$ ergs                  (d) 8000 $\pi$ ergs

Concept Questions :-

Surface tension