Question

A vernier callipers has its main scale graduated in
mm and 10 divisions on its vernier scale are equal
in length to 9 mm. When the two jaws are in contact,
the zero of vernier scale is ahead of zero of main
scale and 3rd division of vernier scale coincides with
a main scale division. Find : (i) the least count and
(ii) the zero error of the vernier callipers.​

Answer 1

$\huge\mathfrak\red{Answer}$

FOR A GENERAL VERNIER CALLIPER.

ONE MAIN SCALE DIVISION IS 1mm.

IN A VERNIER CALLIPER BOTH MAIN SCALE AND VERNIER SCALE HAVE 10DIVISIONS.

IN THIS CASE:

10 DIVISION OF VERNIER SCALE = 9mm.

THEREFORE 1 DIVISION = 9/10 mm.

1 DIVISION OF MAIN SCALE = 1mm.

NOW, - COMING TO QUESTION:

(i)--- LEAST COUNT OF A VERNIER CALLIPER

IS EQU TO 1MSD-1VCD.

FOR THIS VERNIER CALLIPER WE HAVE.

L. C= 1 - 9/10

= 0.1mm.

= 0.01cm.

THEREFORE LEAST COUNT OF GIVEN VERNIER CALLIPER IS 0.01cm.

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(ii) - NOW IF THE ZERO OF VERNIER SCALE IS AHEAD OF ZERO OF MAIN SCALE THEN WE SAY THAT THE ZERO ERROR WILL BE POSITIVE.

FORMULA TO FIND ZERO ERROR OF A GENERAL VERNIER CALLIPER = n ×L.C

WHERE n is the number of vernier scale division which coincides with main scale division.

IN THIS CASE

ZERO ERROR = 3 × 0.1mm

= +0.3mm.

THEREFORE ZERO ERROR OF GIVEN VERNIER CALLIPER IS 0.3mm.

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BY SCIVIBHANSHU

THANK YOU

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