Question

The main scale reading of a screw gauge is 2 mm and the circular scale reading is 45. If the least count is 0.01 mm, what is the actual reading?

Options

• 2.45 mm

• 2.045 mm

• 2.45 cm

• 0.245 mm

Answer 1

2.45 mm

Explanation:

Actual Reading = MSR + (CSR × LC) = 2 + (45 × 0.01) = 2 + 0.45 = 2.45 mm. The circular scale reading is multiplied by the least count and added to the main scale reading to get the precise measurement.