Question
Q. A Vernier callipers has its main scale of 1 cm equally divided into 10 equal parts. 20 vernier scale divisions is equal to 19 main scale divisions. Using this vernier a student measures the diameter of wire. He found that main scale reads 2 small divisions and 4th division of vernier scale coincide with a main scale division. The diameter of the wire is
(a) 2.02 mm
(b) 2. 2 mm
(c) 2.5 mm
(d) 2.1 mm