Question

The vernier scale of travelling microscope has 50 divisions which coincides with 49 main scale division. If each main scale division is 0.5 mm, then the least count of the microscope is

• A. 0.01 mm
• B. 0.01 cm
• C. 0.5 cm
• D. 0.5 mm

Answer 1

Answer: (A)

0.01 mm

Answer 2

Number of divisions on the vernier scale = 50
Number of divisions on the main scale = 49
Measurement of one main scale division = 0.5 mm
To find the difference between one main scale division and one vernier scale division, we can use the formula:
Difference = Measurement of one main scale division / Number of divisions on the main scale
Difference = 0.5 mm / 49 = 0.0102 mm
Therefore, the least count of the microscope is approximately 0.0102 mm. Since the options provided are in different units, we can convert it to cm:
Least count = 0.0102 mm = 0.0102 cm
So, the correct answer is (A) 0.01 mm.