If the number of divisions on the circular scale is 100 and number of full rotations given to screw is 8 and distance moved by the screw is 4 mm, then what will be least count of the screw gauge ?

Explanation

To find the least count of the screw gauge, we can follow these steps:

### Step 1: Understand the concept of pitch
The pitch of the screw gauge is defined as the distance moved by the screw in one complete rotation.

### Step 2: Calculate the pitch
Given:
- Distance moved by the screw = 4 mm
- Number of full rotations = 8

Using the formula for pitch:
\[ \text{Pitch} = \frac{\text{Distance moved}}{\text{Number of rotations}} = \frac{4 \text{ mm}}{8} = 0.5 \text{ mm} \]

### Step 3: Calculate the least count
The least count of the screw gauge is given by the formula:
\[ \text{Least Count} = \frac{\text{Pitch}}{\text{Number of divisions on the circular scale}} \]
Given:
- Number of divisions on the circular scale = 100

Substituting the values:
\[ \text{Least Count} = \frac{0.5 \text{ mm}}{100} = 0.005 \text{ mm} \]

### Final Answer
Thus, the least count of the screw gauge is **0.005 mm**.

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