Assertion : Absolute error may be negative or positive.
Reason : Absolute error is the difference between the real value and the measured value of a physical quantity.

Options

A. If both Assertion and Reason are correct and Reason is the correct explaination of Assertion.
B. If both Assertion and Reason are correct but Reason is not the correct explaination of Assertion.
C. If Assertion is true but Reason is false.
D. If Assertion is false but Reason is true.

Answer

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

### Step 1: Understand the Assertion
The assertion states: "Absolute error may be negative or positive."

- **Explanation**: Absolute error is defined as the difference between the real (true) value of a quantity and the measured value. Depending on whether the measured value is greater than or less than the real value, the absolute error can indeed be positive or negative.

### Step 2: Understand the Reason
The reason states: "Absolute error is the difference between the real value and the measured value of a physical quantity."

- **Explanation**: This statement correctly describes what absolute error is. It is calculated as:
\[ \text{Absolute Error} = \text{Real Value} - \text{Measured Value} \]
This formula shows that if the measured value is less than the real value, the absolute error will be positive, and if the measured value is greater than the real value, the absolute error will be negative.

### Step 3: Conclusion
Both the assertion and reason are correct. The reason accurately explains why the assertion is true. Therefore, we conclude that:

- Both the assertion and the reason are correct, and the reason is the correct explanation for the assertion.

### Final Answer
The correct option is option one, which states that both the assertion and reason are correct, and the reason is the correct explanation for the assertion.

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