If the on a -gauge is given six rotations, it moves by 3 mm on the main scale. If there are 50 divisions on the circular scale the least count of the ***** gauge is :
(1) 0.001 mm
(2) 0.001 cm
(3) 0.02 mm
(4) 0.01 cm
Answer is (2) 0.001 cm
Given on six rotation, reading of main scale changes by 3mm.
∴ 1 rotation corresponds to (1/2) mm
Also no. of division on circular scale = 50.
∴ Least count of the ***** gauge will be
(0.5/50) mm = 0.001 cm.
