Verified Solution • 2025–26 Session moderate

QJEEM18Ph09ce: JEE Main 2018 Physics - Class 12 JEEM18Ph09ce Solution: In a screw gauge, 5 complete rotations of the screw cause it to …

In a screw gauge, 5 complete rotations of the screw cause it to move a linear distance of 0.25 cm. There are 100 circular scale divisions. The thickness of a wire measured by this screw gauge gives a reading of 4 main scale divisions and 30 circular scale divisions. Assuming negligible zero error, the thickness of the wire is :

Multiple Choice Options

  • A 0.4300 cm
  • B 0.2150 cm
  • C 0.3150 cm
  • D 0.0430 cm

Step-by-Step Verified Solution

5 complete rotations = 0.25 cms

So, 1 complete rotation of screw = 0.05 cm

∴ 1 main scale division = 0.05 cm

1 circular scale = 0.05100 = 5 × 10−4 cm

Thickness of a wire

= 4 main scale and 30 circular scale divisions

= 4 × 0.05 + 30 × 5 × 10 −4

= 0.2150 cm.

Related Learning Resources & Exam Preparation