Streamline flow is more likely for liquids with

(a) high density. (b) high viscosity.
(c) low density. (d) low viscosity.

Choose the correct option:

1. (a), (b) 2. (c), (d)
3. (b), (c) 4. (a), (d)
Hint: Re=ρvDμ

Explanation: To determine the conditions under which streamline flow is more likely for liquids, we need to analyze the concept of Reynolds number (Re). The Reynolds number is given by;
Re=ρvDμ
where ρ=  density of the fluid, v=  velocity of the fluid, D= diameter of a pipe, μ= dynamic viscosity of the fluid.
We know that the greater the coefficient of viscosity of a liquid, more will be the velocity gradient. So, each line of flow can be easily differentiated. Also, the higher the coefficient of viscosity, the lower the Reynolds number (Re). Thus, the flow is more likely to be streamlined. Therefore, streamline flow is more likely for liquids with high viscosity and low density.
Hence, option (3) is the correct answer.