Topic: Heat Transfer
A hot liquid is kept in a big room. Its temperature (theta) is plotted as a function of time (t), which of the following curve may represent the plot?
- A. Curve d
- B. Curve b
- C. Curve c
- D. Curve a
Answer: D. Curve a
Explanation: The graph of the temperature of a cooling body versus time is known as a cooling curve. According to Newton's law of cooling, the temperature falls exponentially with time, represented by the general equation T(t) = T_A + (T_H - T_A)e^(-kt). This exponential decay corresponds to curve 'a'.