Question

Fig. 1.15 above shows the reading obtained while
measuring the diameter of a wire with a screw
gauge. The screw advances by 1 division on main
scale when circular head is rotated once.

Find : (i) pitch of the screw gauge,
(ii) least count of the screw gauge, and
(iii) the diameter of the wire.​

Answer 1

Pitch is the linear distance traveled by one complete rotation of circular scale.

Pitch is the linear distance traveled by one complete rotation of circular scale. Since, 1 division travel in main scale so the pitch will be 1 mm.

Pitch is the linear distance traveled by one complete rotation of circular scale. Since, 1 division travel in main scale so the pitch will be 1 mm. Least count, LC=p/n

Pitch is the linear distance traveled by one complete rotation of circular scale. Since, 1 division travel in main scale so the pitch will be 1 mm. Least count, LC=p/n Here, pitch p=1mm and total number of circular divisions n=50

Pitch is the linear distance traveled by one complete rotation of circular scale. Since, 1 division travel in main scale so the pitch will be 1 mm. Least count, LC=p/n Here, pitch p=1mm and total number of circular divisions n=50 So, LC=1/50=0.02 mm

Pitch is the linear distance traveled by one complete rotation of circular scale. Since, 1 division travel in main scale so the pitch will be 1 mm. Least count, LC=p/n Here, pitch p=1mm and total number of circular divisions n=50 So, LC=1/50=0.02 mmDiameter of the wire, d= main scale reading (MSR ) +[ circular scale reading (CSD) ×LC]=4+[47×0.02]=4.94 mm