
The figure shows two diagrams of same screw gauge, in first case nothing is kept in its jaw and in second a small ball is kept between jaws which diameter is required to be measured. The number of circular divisions on the shown screw gauge is . It moves on main scale for one complete rotation and main scale has marks. The diameter of the balls is



Important Questions on Measurement



The readings of the main scale and the circular scale, for a thin sheet, are and respectively, the thickness of this sheet is:

S.No. | MS (cm) | VS divisions |
1. | 0.5 | 8 |
2. | 0.5 | 4 |
3. | 0.5 | 6 |
If the zero error is - 0.03 cm, then mean corrected diameter is:





The figure of a centimetre scale below shows a particular position of the Vernier calipers. In this position, the value of shown in the figure is (figure is not to scale):






The vernier scale used for measurement has a positive zero error of If while taking a measurement it was noted that on the vernier scale lies between and . Vernier coincidence is then the correct value of measurement is
(least count)




There are two vernier calipers both of which have divided into equal divisions on the main scale. The Vernier scale of one of the calipers has equal divisions that correspond to main scale divisions. The Vernier scale of the other caliper has equal divisions that correspond to main scale divisions. The readings of the two calipers are shown in the figure. The measured values (in ) by calipers and respectively, are

