A student performs an experiment to determine the Young’s modulus of a wire, exactly 2m long, by Searle’s method. In a particular reading, the student measures the extension in the length of the wire to be 0.8mm with an uncertainty of at a load of exactly 1.0kg. The student also measures the diameter of the wire to be 0.4mm with an uncertainty of . Take (exact). The Young’s modulus obtained from the reading is[ Take ]
Given Length of wire
Extension=
Uncertainty =0.05 mm
Diameter of the wire
Mass
Acceleration due to gravity
Using Hooke’s Law
Also
Where L= length of the wire
l= elongation of the wire
d= diameter of the wire
From equation (1)
Taking log on both sides
Now partially differentiating
Therefore, the correct answer is (B).