Question

The length of a wire is measured to be (10.25 ± 0.01) cm. The radius is measured to be (0.840 ± x) cm. If the relative error, in the volume of the wire, is calculated to be 0.0158, the least count of the instrument, used for measuring the radius, is 

(1) 0.004 cm (Incorrect) 

(2) 0.002 cm (Correct) 

(3) 0.001 cm (Incorrect) 

(4) 0.0005 cm

Answer 1

(2) 0.002 cm (Correct) 

Thus the least count of the instrument, used for measuring r, is 0.002 cm.