Two small drops of mercury, each of radius r, coalesce to form a single large drop. The ratio of the total surface energies before and after the change is

1. $1:{2}^{1/3}$                          2.

3. 2:1                              4. 1:2

Concept Questions :-

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

Difficulty Level:

The work done in blowing a soap bubble of radius 0.2 m is (the surface tension of soap solution being 0.06 N/m)

(a)                  (b)

(c)                  (d) None of these

Concept Questions :-

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

Difficulty Level:

A liquid film is formed in a loop of area 0.05 ${\mathrm{m}}^{2}$. Increase in its potential energy will be (T = 0.2 N/m)

(a)               (b)

(c)                (d) None of these

Concept Questions :-

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

Difficulty Level:

In order to float a ring of area 0.04 ${\mathrm{m}}^{2}$ in a liquid of surface tension 75 N/m, the required surface energy will be

(a) 3 J                   (b) 6.5 J
(c) 1.5 J                 (d) 4 J

Concept Questions :-

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

Difficulty Level:

If two soap bubbles of equal radii r coalesce then the radius of curvature of interface between two bubbles will be

(a) r                                  (b) 0
(c) Infinity                         (d) 1/2r

Concept Questions :-

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

Difficulty Level:

When the temperature is increased the angle of contact of a liquid

(a) Increases

(b) Decreases

(c) Remains the same

(d) First increases and then decreases

Concept Questions :-

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

Difficulty Level:

The angle of contact between glass and mercury is

(a) 0°                                     (b) 30°
(c) 90°                                   (d) 135°

Concept Questions :-

Surface tension

Difficulty Level:

A mercury drop does not spread on a glass plate because the angle of contact between glass and mercury is

(a) Acute                    (b) Obtuse
(c) Zero                      (d) $90°$

Concept Questions :-

Surface tension

Difficulty Level:

The liquid meniscus in the capillary tube will be convex if the angle of contact is

(a) Greater than 90°                                 (b) Less than 90°
(c) Equal to 90°                                  (d) Equal to 0°

Concept Questions :-

Capillary rise

Difficulty Level:

The value of contact angle for kerosene with solid surface.
(a) 0°                                     (b) 90°
(c) 45°                                   (d) 33°

Concept Questions :-

Surface tension