Q. A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 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 cm, the correct diameter of the ball is
A) 0.053 cm
B) 0.525 cm
C) 0.521 cm
D) 0.529 cm
Explanation
[Solution] Reading = 0.5 + 25 × 0.001 = 0.525 cm; correct = 0.525 - (-0.004) = 0.529 cm. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.