Which of the following statements `"is"//"are"` correct?
I. The error in measurement of length can be caused by positioning the eye incorrectly.
II. The SI unit of length is metre and 1 m = 1000 cm.
III. The smallest length that could be measured by different devices may be different.

Options

A. I only
B. III only
C. I and II only
D. I and III only

Explanation

To determine which of the statements are correct, let's analyze each statement one by one.

### Step 1: Analyze Statement I
**Statement I:** "The error in measurement of length can be caused by positioning the eye incorrectly."

- When measuring lengths, if the eye is not positioned directly in line with the measurement scale (like a ruler), it can lead to parallax error. This means that the reading can be inaccurate due to the angle at which the measurement is taken.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Statement II
**Statement II:** "The SI unit of length is metre and 1 m = 1000 cm."

- The SI unit of length is indeed the meter (m). However, it is important to note that 1 meter is equal to 100 centimeters (cm), not 1000 cm.

**Conclusion:** This statement is **incorrect**.

### Step 3: Analyze Statement III
**Statement III:** "The smallest length that could be measured by different devices may be different."

- Different measuring devices have different levels of precision. For example, a ruler may measure to the nearest millimeter, while a micrometer can measure to the nearest micrometer. Thus, the smallest measurable length can vary depending on the device used.

**Conclusion:** This statement is **correct**.

### Final Conclusion
- **Correct Statements:** I and III are correct.
- **Incorrect Statement:** II is incorrect.

### Answer
The correct statements are I and III.

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