Advertisements
Advertisements
Question
Define the least count of vernier callipers. How do you determine it?
Solution
The least count of vernier callipers is equal to the difference between the values of one main scale division and one vernier scale division.
Let n divisions on vernier callipers be of length equal to that of (n - 1) divisions on the main scale and the value of 1 main scale division be x. Then,
Value of n divisions on vernier = (n - 1) x
Alternatively, value of 1 division on vernier = `((n - 1)"x")/n`
Least count = `x - ((n - 1)"x")/n = x/n`
L.C. = `"(Value of one main scale division)"/"(Total no. of divisions on vernier callipers)"`
Value of one main scale division = 1 mm
Total no. of divisions on vernier = 10
Therefore, L.C. = `(1 "mm")/10` = 0.1 mm = 0.01 cm
APPEARS IN
RELATED QUESTIONS
Name the two scales of a vernier callipers and explain how it is used to measure length correct up to 0.01 cm.
A screw gauge has 50 divisions on its circular scale and its screw moves by 1 mm on turning it by two revolutions. When the flat end of the screw is in contact with the stud, the zero of the circular scale lies below the base line and 4th division of the circular scale is in line with the base line. Find
(i) The pitch,
(ii) The least count and
(iii) The zero error of the screw gauge
A screw has a pitch equal to 0.5 mm. What should be the number of divisions on its head so as to read correctly up to 0.001 mm with its help?
Why is the metre length in terms of the wavelength of light considered more accurate?
(a) A vernier scale has 20 divisions. It slides over the main scale, whose pitch is 0.5 mm. If the number of divisions on the left hand of the zero of vernier on the main scale is 38 and the 18th vernier scale division coincides with the main scale, calculate the diameter of the sphere, held in the jaws of vernier callipers.
(b) If the vernier has a negative error of 0.04 cm, calculate the corrected radius of the sphere.
State the formula for determining least count for a vernier callipers.
How will you measure the least count of vernier caliper?
