99 Percentile Qs Bank for JEE MainPhysicsExperimental Physics
A screw gauge with a pitch of 0.5 mm and a circular scale with 50 divisions is used to measure the thickness of a thin sheet of aluminum. Before starting the measurement, it is found that when the two jaws of the screw gauge are brought in contact, the 45 t h division coincides with the main scale line and that the zero of the main scale is barely visible. What is the thickness (in m m ) of the sheet if the main scal
Correct answer
85
Step-by-step solution
Least count, L C = 0 . 5 50 = 0 . 01 mm Zero error, Z E = 50 - 45 × 0 . 01 = - 0 . 05 mm Main Scale Reading M S R = 0.5 mm Thickness, t = 0 . 5 mm + 30 × 0 . 01 mm - - 0 . 05 mm t = 0 . 85 mm