The thin metallic strip of vernier calipers moves downward from top to bottom in such a way that it just touches the surface of beaker. Main scale reading of caliper is 6 . 4   cm whereas its vernier constant is 0.1 mm . The 4 th of vernier scale division is coinciding with main scale division. The actual depth of beaker in mm is (when zero of vernier coincides with zero of main scale),

Step-by-step solution

We are measuring the depth from metallic strip of vernier calipers. Given, The least count of vernier calipers LS = 0 . 1   mm = 0 . 01   cm Main scale reading MSR = 6 . 4   cm Vernier scale reading VSR = 4 So the reading of the depth, D = MSR + ( VSR × LC ) = 6 . 4 + ( 4 × 0 . 01 ) = 6 . 44   cm Because, there is no zero error, so depth will be same as above.