The number of circular divisions on the shown screw gauge is 50. It moves 0.5 mm on main scale for one complete rotation. Main scale reading is 2. The diameter of the ball is

Question

The number of circular divisions on the shown screw gauge is 50. It moves 0.5 mm on main scale for one complete rotation. Main scale reading is 2. The diameter of the ball is (A) 2.25 mm (B) 2.20 mm (C) 1.20 mm (D) 1.25 mm

Tardigrade Admin · Accepted Answer

Zero error =5×(0.5/50)=0.05 mm Actual measurement =2×0.5 mm+25×(0.5/50)-0.05 mm =1 mm+0.25 mm-0.05 mm=1.20 mm

Q. The number of circular divisions on the shown screw gauge is $50$ . It moves $0.5 mm$ on main scale for one complete rotation. Main scale reading is $2$ . The diameter of the ball is

$2.25 mm$

$2.20 mm$

$1.20 mm$

$1.25 mm$

Zero error $= 5 \times \frac{0.5}{50} = 0.05 mm$
Actual measurement
$= 2 \times 0.5 mm + 25 \times \frac{0.5}{50} - 0.05 mm$
$= 1 mm + 0.25 mm - 0.05 mm = 1.20 mm$

Q. The number of circular divisions on the shown screw gauge is 50. It moves 0.5mm on main scale for one complete rotation. Main scale reading is 2. The diameter of the ball is

2.25mm

2.20mm

1.20mm

1.25mm