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Physics · PYQ NEET UG 2018
हिन्दीA student measured the diameter of a small steel ball using a screw gauge of least count \( 0.001\text{ cm} \). The main scale reading is \( 5\text{ mm} \) and zero of circular scale division coincides with \( 25 \) divisions above the reference level. If screw gauge has a zero error of \( -0.004\text{ cm} \), the correct diameter of the ball is
Correct answer · Option D
\( 0.529\text{ cm} \)
Explanation
Measured reading = MSR + (CSR \times LC) = \( 0.5\text{ cm} + 25 \times 0.001\text{ cm} = 0.525\text{ cm} \). Correct diameter = Measured reading - Zero error = \( 0.525\text{ cm} - (-0.004\text{ cm}) = 0.529\text{ cm} \).
