In winters the average temperature of a city is −1∘C. There is a big lake in the middle of the city. The temperature in the lake, ____ with an increase in depth.
increases
It is given that the average temperature of a city is −1∘C. The surface water or top layer of the lake freezes when the temperature reaches 0∘C.
We know that ice floats on water. So the top layer of the lake freezes and acts as an insulator for the water below it. The temperature in the lake is least at the top and increases as the depth increases. This anomalous behaviour of water helps the aquatic animals.