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A student determined Young's Modulus of elasticity using the formula Y = MgL³ / 4bd³δ. The value of g is taken to be 9.8 m/s², without any significant error, his observation are as following.

1. Mass (M): Least count of the Equipment used for measurement 1 g; Observed value 2 kg
2. Length of bar (L): Least count of the Equipment used for measurement 1 mm; Observed value 1 m
3. Breadth of bar (b): Least count of the Equipment used for measurement 0.1 mm; Observed value 4 cm
4. Thickness of bar (d): Least count of the Equipment used for measurement 0.01 mm; Observed value 0.4 cm

Correct answer: Thickness of bar (d): Least count of the Equipment used for measurement 0.01 mm; Observed value 0.4 cm

Solution

The thickness of the bar (d) is crucial for calculating Young's Modulus, as it directly affects the stiffness of the material. The observed value of 0.4 cm and a least count of 0.01 mm indicate a precise measurement, which is essential for accurate results in the formula.

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