Q: When the two jaws of a vernier calliper are in touch , zero of vernier scale lies to the right of zero of main scale and coinciding vernier division is 3 . If vernier constant is 0.1 mm , the zero correction is

(a) -0.03 cm

(b) +0.03 cm

(c) -0.03 mm

(d) + 0.03 mm

Sol: As Zero of vernier scale is to the right of zero of main scale , therefore , zero correction is negative .

Its magnitude = 3 × 0.1 mm = 0.3 mm = 0.03 cm

Ans: (a)