Question

is it possible for someone to explain me ... how to take reading from vernier callipers and least count ?!


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class 11 ​

Answer 1

$\sf \Large Answer!!$

Least count of vernier callipers:-

It is equal to the difference between the values of one main scale division and one vernier scale division.

Least count = Value of one main scale division (x) ÷ Total number of divisions on vernier (n)

The least count on vernier callipers can be decreased by:-

→ Increasing the number of divisions on the vernier scale

→ Decreasing the value of one division on main scale

Experiment → Measurement of length of an object with a vernier callipers.

Procedure:-

(a) Find the least count and zero error of the vernier callipers.

(b) Move the jaw $\sf J_{2}$ away from the jaw $\sf J_{1}$ and place the object to be measured between the jaws. Move the jaw $\sf J_{2}$ towards the jaw $\sf J_{1}$ till it touches the object. Tighten the screw S to fix the vernier scale in its position.

(c) Note the main scale reading.

(d) Note that division p on the vernier scale which coincides or is in line with any division of the main scale. Vernier scale reading = p × Least count

(e) Add the vernier scale reading to the main scale reading. This gives the observed length.

(f) Repeat it two times and record the observations.

Observation:-

Total number of divisions on vernier scale n = ...

Value of one division on main scale x = ... cm

Least count = x ÷ n = ... cm

Zero error = ... cm

Mean observed length = ... cm

Observed length = main scale reading + (vernier division p coinciding with any division on the main scale) × least count

True length = observed length - zero error (with sign)