Advertisements
Advertisements
Question
State the formula for calculating the least count of screw.
Advertisements
Solution
Least count of screw
= `"Pitch"/"Number of circular scale divisions"`
E.g. If pitch of screw is 1 mm and there are 100 divisions on the circular scales, then
Least count = `(1 "mm")/100` = 0.01 mm
L.C. = 0.01 mm or 0.001 cm
APPEARS IN
RELATED QUESTIONS
The wavelength of light of a particular colour is 5800 Å.
Express it in nanometre.
Draw a neat and labelled diagram of a screw gauge.
Name its main parts and state their functions.
A pendulum completes 2 oscillations in 5 s. What is its time period? If g = 9.8 m s-2, find its length.
Define the term pitch.
Define the term least count as applied to a vernier callipers.
Figure shows a screw gauge in which circular scale has 200 divisions. Calculate the least count and radius of the wire.

A micrometre screw gauge has a negative zero error of 8 divisions. While measuring the diameter of a wire the reading on the main scale is 3 divisions and the 24th circular scale division coincides with baseline.
If the number of divisions on the main scale are 20 to a centimetre and circular scale has 50 divisions, calculate
- pitch
- observed diameter.
- least count
- corrected diameter.
A micrometre screw gauge has a negative zero error of 7 divisions. While measuring the diameter of a wire the reading on the main scale is 2 divisions and 79th circular scale division coincides with baseline.
If the number of divisions on the main scale is 10 to a centimetre and circular scale has 100 divisions, calculate
- pitch
- observed diameter
- least count
- corrected diameter.
State whether the following statement is true or false by writing T/F against it.
The diameter of a wire can be measured more accurately by using vernier calipers than by a screw gauge.
