Question

The property of liquid to resist its flow is called?
A) Viscosity
B) Rigidity
C) Flow
D) Thickness

Answer 1

A liquid has various properties. But here, this is particularly referring to the resistance of flow. Different liquids have different resistance towards flow. It is a frictional phenomenon between the layers of liquid.

Complete answer:
We need to understand the individual terms in order to find out the correct answer. For this purpose, first we will understand viscosity
It is a measure of resistance to flow of liquid. It is described by the internal friction of a moving fluid. If you fill the same cup with water, the cup will drain much more quickly. A fluid with low viscosity can flow easily. Its molecular makeup results in very little friction when it is in motion. Even Gases have viscosity, though it is a little harder to notice it in normal circumstances.
Now the second term is rigidity.
The term rigidity means, it is a state of being rigid. It referred to being stiff and inflexible. Both rigid and rigidity can be used in both literal and figurative ways. An object might be described as rigid if they are very stiff and can not bend easily.
Hence, the answer is option A.

Note:
This is often expressed by an example. Imagine a cup with a hole in the bottom. If you then pour honey into the cup, You will find that the cup drains very slowly. That is because the viscosity of honey is large compared to other liquids viscosity.