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. $2^{1/3} :1$

3. 2:1

4. 1:2

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

1. r                                 

2. 0

3. Infinity                         

4. 1/2r

The angle of contact between glass and mercury is

1. 0°

2. 30°

3. 90°

4. 135°

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

1. Acute

2. Obtuse

3. Zero

4. $90°$

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

1. Greater than 90°

2. Less than 90°

3. Equal to 90°

4. Equal to 0°

The value of contact angle for kerosene with a solid surface.

1. 0°

2. 90°

3. 45°

4. 33° 

Nature of meniscus for liquid of $0^0$ angle of contact

1. Plane

2. Parabolic

3. Semi-spherical

4. Cylindrical

A liquid wets a solid completely. The meniscus of the liquid in a sufficiently long tube is 

1. Flat

2. Concave

3. Convex

4. Cylindrical

For which of the two pairs, the angle of contact is same

1. Water and glass; glass and mercury

2. Pure water and glass; glass and alcohol

3. Silver and water; mercury and glass

4. Silver and chromium; water and chromium

If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of the container is -

1. Acute angle

2. Obtuse angle

3. 90°

4. 0°