Assertion: According to Newton's law of cooling, the rate of loss of heat, `-dQ//dt` of the body is directly proportional to the difference of temperature.
Reason :This law holds for all type of temperature differences.

Options

A. law of thermometry
B. Newton's law of cooling
C. law of calorimetry
D. zeroth law

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that according to Newton's law of cooling, the rate of loss of heat (dQ/dt) of a body is directly proportional to the difference in temperature (T - T₀) between the body and its surroundings. Mathematically, this can be expressed as:
\[ \frac{dQ}{dt} = -k(T - T_0) \]
where \( k \) is a proportionality constant, \( T \) is the temperature of the body, and \( T_0 \) is the temperature of the surroundings.

### Step 2: Evaluate the Reason
The reason states that this law holds for all types of temperature differences. However, this is not true. Newton's law of cooling is applicable primarily for small temperature differences. For large temperature differences, the law does not hold accurately, and other factors may need to be considered.

### Step 3: Conclusion
- The assertion is **true**: It correctly describes Newton's law of cooling.
- The reason is **false**: It incorrectly states that the law applies to all temperature differences.

### Final Answer
The assertion is true, but the reason is false.

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