The distance moved by the screw of a screw gauge is 2 mm in four rotations and there are 50 divisions on its cap. When nothing is put between its jaws, 30th division of circular scale coincides with the reference line, with zero of circular scale lying above the reference line. When a plate is placed between the jaws, the main scale reads 2 divisions and the circular scale reads 20 divisions. The thickness of the plate is

Question

The distance moved by the screw of a screw gauge is 2 mm in four rotations and there are 50 divisions on its cap. When nothing is put between its jaws, 30th division of circular scale coincides with the reference line, with zero of circular scale lying above the reference line. When a plate is placed between the jaws, the main scale reads 2 divisions and the circular scale reads 20 divisions. The thickness of the plate is (A) 1.5 textmm (B) 1.2 textmm (C) 1.4 textmm (D) 1.6 textmm

Tardigrade Admin · Accepted Answer

Pitch = (1/2) textmm least count = (0.5 textmm/50) = 0.01 textmm Reading = [. 2 × (1/2) + 20 × 0.01 - (. - 30 × 0.01 .) ]. = 1.5 textmm

$1.5 mm$

$1.2 mm$

$1.4 mm$

$1.6 mm$

Pitch $= \frac{1}{2} mm$
least count $= \frac{0.5 mm}{50} = 0.01 mm$
Reading $= [2 \times \frac{1}{2} + 20 \times 0.01 - (- 30 \times 0.01)] = 1.5 mm$

1.5mm

1.2mm

1.4mm

1.6mm

Pitch =21​mm least count =500.5mm​=0.01mm Reading =[2×21​+20×0.01−(−30×0.01)]=1.5mm

$1.5 mm$

$1.2 mm$

$1.4 mm$

$1.6 mm$

Pitch $= \frac{1}{2} mm$
least count $= \frac{0.5 mm}{50} = 0.01 mm$
Reading $= [2 \times \frac{1}{2} + 20 \times 0.01 - (- 30 \times 0.01)] = 1.5 mm$