Question

Temperature of a body \( \theta \) is slightly more than the temperature of the surroundings \( \theta_0 \). Its rate of cooling \( R \) versus temperature \( \theta \) graph should be 

• A. Option a
• B. Option b
• C. Option c
• D. Option d

Hint:

Cooling law: Rate proportional to excess temperature.

Answer 1

The Correct Option is B

Concept:
Newton’s law of cooling:
\[ R = -k(\theta - \theta_0) \]

Step 1: Relation with temperature
Rate of cooling proportional to temperature difference.

Step 2: Graph vs \( \theta \)
\[ R \propto (\theta - \theta_0) \]
So linear dependence.

Step 3: Shape
Straight line increasing with \( \theta \).