Question

If in winter season, the surface temperature of a lake is $1{}^{\circ }\text{C}$, the temperature at the bottom of the lake can be

• A. $1{}^{\circ }\text{C}$
• B. $0{}^{\circ }\text{C}$
• C. $4{}^{\circ }\text{C}$
• D. All values less than $1{}^{\circ }\text{C}$ are possible

Answer 1

The correct option is C $4{}^{\circ }\text{C}$

We know that more dense fluid settles below the less dense fluid. Therefore, at the bottom of the lake, water will have lower density than the surface.
Also, we know, at $4{}^{\circ }\text{C}$, the density of water is maximum as volume is minimum. And below $4^{\circ }\text{C}$, the density decreases with decrease in temperature.


Hence, the temperature at the bottom has to be greater than $1^{\circ }\text{C}$. i.e Only $\left(c\right)$ is a possible option.