Which of the following statements is NOT correct about surface tension?

Question

Question

This question was previously asked in

SSC CGL 2023 Tier-I Official Paper (Held On: 18 Jul 2023 Shift 1)

Surface tension is typically measured in dynes/cm.
The shape of water drop is spherical due to surface tension.
At room temperature, surface tension of water is less than ethyl alcohol.
The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension.

Answer 1

The correct answer is At room temperature, surface tension of water is less than ethyl alcohol.

Key Points

Surface tension is indeed typically measured in dynes/cm, which indicates the force required to break a film of length 1 cm. Hence, option 1 is correct.
The shape of a water droplet is spherical due to surface tension. Hence, option 2 is also correct.
The spherical shape is the result of surface tension minimizing the surface area of the drop, as the sphere is the shape that has the least surface area for a given volume.
Contrary to statement 3, at room temperature, the surface tension of water is actually higher than that of ethyl alcohol. For example, water at 20°C has a surface tension of 72.8 dynes/cm, while that for ethyl alcohol is 22.3 dynes/cm.
The cohesive forces between liquid molecules are indeed responsible for the phenomenon known as surface tension. These forces cause the liquid to behave as though it is covered with a stretched elastic sheet, a property known as surface tension. Hence, option 4 is also correct.