Question

UNITS AND MEASUREMENTS
15. The density of a solid ball is to be determined in
an experiment. The diameter of the ball is measured
with a screw gauge, whose pitch is 0.5 mm and there
are 50 divisions on the circular scale. The reading on
the main scale is 2.5 mm and that on the circular scale
is 20 divisions. If the measured mass of the ball has a
relative error of 2%, the relative percentage error in the
density is
(a) 0.9%
(C) 3.1%
(b) 2.4%
(d) 4.2%
[IIT 2011​

Answer 1

Answer:

The density of a solid ball is to be determined in an experiment. The diameter of the ball is measured with a screw gauge, whose pitch is 0.5 mm and there are 50 divisions on the circular scale. The reading on the main scale is 2.5 mm and that on the circular scale is 20 divisions. If the measured mass of the ball has a relative error of 2%, then the relative percentage error in the density is:

6