JEE Main20211 Sep 2021Evening ShiftPhysicsMathematics in PhysicsActual
A student determined Young's Modulus of elasticity using the formula Y = M g L 3 4 bd 3 δ . The value of g is taken to be 9 . 8 m s - 2 without any significant error, his observations are as following. Physical Quantity Least count of the Equipment used for measurement Observed Value Mass ( M ) 1 g 2 kg Length of bar ( L ) 1 mm 1 m Breadth of bar ( b ) 0 . 1 mm 4 cm Thickness of bar ( d ) 0 . 01 mm 0 . 4 cm
Options
- A0 . 155
- B0 . 0083
- C0 . 083
- D0 . 0155
Correct answer
D. 0 . 0155
Step-by-step solution
Y = M g L 3 4 bd 3 δ ∆ Y Y = ∆ M M + 3 ∆ l 1 + ∆ b b + 3 ∆ d d + ∆ δ δ ⇒ ∆ Y Y = 0 . 0005 + 3 × 0 . 001 + 0 . 0025 + 3 × 0 . 0025 + 0 . 002 = 0 . 0155