The SI unit of entropy is

Options

A. joule/kelvin
B. newton-meter
C. calorie/second
D. joule/calorie

Explanation

To determine the SI unit of entropy, we can follow these steps:

### Step 1: Understand the Concept of Entropy
Entropy is a measure of the amount of energy in a physical system that is not available to do work. It is often associated with the disorder or randomness of a system.

### Step 2: Identify the Formula for Entropy
Entropy (S) can be defined in terms of heat transfer (dq) and temperature (T). The formula is given by:
\[ S = \frac{dq}{T} \]
where:
- \( S \) is the entropy,
- \( dq \) is the infinitesimal amount of heat added to the system,
- \( T \) is the absolute temperature in Kelvin.

### Step 3: Determine the Units of Each Component
- The unit of heat (dq) in the SI system is Joules (J).
- The unit of temperature (T) is Kelvin (K).

### Step 4: Combine the Units
Using the formula for entropy, we can express the units as follows:
\[ \text{Unit of Entropy} = \frac{\text{Joules}}{\text{Kelvin}} = \frac{J}{K} \]

### Step 5: Conclusion
Thus, the SI unit of entropy is Joules per Kelvin (J/K).

### Final Answer
The SI unit of entropy is \( \text{J/K} \) (Joules per Kelvin).

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