Least count =1001mm=0.01mm
zero error =+8×LC=+0.08mm
True reading (Diameter)
=(1mm+72×LC)− (Zero error)
=(1mm+72×0.01mm)−0.08mm
=1.72mm−0.08mm
=1.64mm
therefore, radius =21.64=0.82mm.
JEE Main 2021 — Physics Mechanics
The pitch of the screw gauge is 1mm and there are 100 divisions on the circular scale. When nothing is put in between the jaws, the zero of the circular scale lies 8 divisions below the reference line. When a wire is placed between the jaws, the first linear scale division is clearly visible while 72nd division on circular scale coincides with the reference line. The radius of the wire is
Held on 25 Feb 2021 · Verified 6 Jul 2026.
1.64mm
0.82mm
0.90mm
1.80mm
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