The diagram shows part of a vernier
scale.
What is the reading
on the vernier
scale?
A 6.50 cm
B 6.55 cm
C 7.00 cm
D 7.45 cm
Correct
Answer: B (6.55 cm)
Explanation:
We know that in vernier calipers there is a small scale called vernier scale.
In most of the vernier scales there are 10 divisions marked from 0 to 10. In
some other scales there are 20 divisions. Vernier constant is the measure of
accuracy level of a vernier scale. The formula to find vernier constant is:
Vernier
Constant (V.C) = (1 / No. of divisions)
So, If the no. of divisions
are 10 then the scale can measure up to (1/10) = 0.1 mm accurately and if there
are 20 divisions then (1/20) = 0.05 mm is the accuracy level of the scale. As
vernier constant is a ratio, it does not have any unit. Now to find the reading
we have to add main scale reading with vernier scale reading. To find vernier
scale reading you have to multiply the vernier scale reading with vernier
constant and the value you will get will be in millimeters. So the work out is
as follows:
Reading
= Main Scale Reading + (Vernier Scale reading x vernier constant)
= 6.5
cm + (5 x 0.1) mm
= 6.5
cm + 0.05 cm
= 6.55
cm
