A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it?
(a) A meter scale
(b)A vernier calliper where the 10 divisions in vernier scale matches with 9 divisions in main scale and main scale has 10 divisions in 1 cm
(c) A ***** gauge having 100 divisions in the circular scale and pitch as 1 mm
(d) A ***** gauge having 50 divisions in the circular scale and pitch as 1 mm
