Question

The vernier scale used for measurement has a positive zero error of 0.2 mm. If while taking a measurement it was noted that '0' on the vernier scale lies between 8.5 cm and 8.6 cm, vernier coincidence is 6, then the correct value of measurement is....... cm.

(least count = 0.01 cm)

(1) 8.36 cm

(2) 8.54 cm

(3) 8.58 cm

(4) 8.56 cm

Answer 1

Correct option is (2) 8.54 cm

Positive zero error = 0.2 mm

Main scale reading = 8.5 cm

Vernier scale reading = 6 × 0.01 = 0.06 cm

Final reading = 8.5 + 0.06 – 0.02 = 8.54 cm