Most Important Selected Qs for JEE AdvancedPhysicsExperimental Physics
A screw gauge with a pitch of 1 m m has 100 divisions on its circular scale. When it is used to measure the diameter of a thin wire, the main scale reading is 3 m m and the circular scale reading is 45 . If D is the diameter of the wire in m m, then find the value of D.
Correct answer
3.45
Step-by-step solution
L e a s t c o u n t = P i t c h N o . o f d i v i s i o n = 1 m m 100 = 0.01 m m D i a m e t e r o f w i r e = m a i n s c a l e + c i r c u l a r s c a l e r e a d i n g = 3 m m + L . C × N o . o f d i v i s i o n = 3 m m + 0.01 × 45 D = 3.45 m m