JEE Advanced2014PhysicsExperimental PhysicsActual
During Searle's experiment, zero of the Vernier scale lies between 3.20 × 10 - 2   m and 3.25 × 10 - 2   m of the main scale. The 20 t h division of the Vernier scale exactly coincides with one of the main scale divisions. When an additional load of 2 kg is applied to the wire, the zero of the Vernier scale still lies between 3.20 × 10 - 2   m and 3.25 × 10 - 2   m of the m
Correct answer
4
Step-by-step solution
Y = F L l A since the experiment measures only change in the length of wire ∴ ∆ Y Y × 100 = ∆ l l × 100 From the observation l 1 = M S R + 20 L C l 2 = M S R + 45 L C ⇒ change in lengths = 25 L C and the maximum permissible error in elongation is one LC ∴ ∆ Y Y × 100 = L C 25 L C × 100 = 4