Experiment : For measuring the diameter of small spherical /cylindrical body with the help of a Vernier callipers .
Apparatus : Vernier callipers , Spherical/Cylindrical body
Formula Used : When the body is held the lower jaws of the vernier callipers , let the zero of the vernier scale lies ahead of the mth division of the main scale and nth division of the vernier scale coincides with some division on the main scale then ,
Total Reading = M.S. reading = m + (n × V.C)
How To Perform :
(i) Explore the Vernier Constant (V.C) of the Vernier Calipers .
(ii) Determine the Zero error . Do it three times by opening jaws . If you don’t find any zero error , then record ” zero error nil ”
(iii) Pull the jaw apart , keep the sphere or cylinder between the two jaws and adjust the movable jaws such that it politely ditches the object without applying any extra pressure on it . Tighten the screw attached to the vernier scale .
(iv) Note down the main scale reading just before the zero mark of the vernier scale . This reading is said to be main scale reading (M.S.R)
(v) Note down the Vernier scale division which coincides with some division of the main scale .
(vi) Repeat steps (iv) & (v) at various positions ai perpendicular direction .
(vii) Repeat the observation at least thrice & record it in the table .