With an increase in temperature, the viscosity of:
(a) gases decreases.
(b) liquids increases.
(c) gases increases.
(d) liquids decreases.
Which of the following options is/are correct?

1. (b, c) 2. (a, d)
3. (c, d) 4. (a, b)
(3) Hint: The viscosity of a liquid depends on the intermolecular forces and the viscosity of the gases depends on the movement of the molecules.
Step 1: Find the variation of viscosity of the liquids with temperature.
For liquids, the coefficient of viscosity, ηliquid1T
i.e. with an increase in temperature, ηliquid decreases.
Step 2: Find the variation of viscosity of the gases with temperature.
For gases, the coefficient of viscosity, ηgasesT
i.e. with an increase in temperature, ηgases increases.