To determine the volume of a cylinder using Vernier calipers
Apparatus
Vernier callipers, solid cylinder.
Diagram
Vernier callipers
Vernier callipers is used for measuring the length and diameter accurately up to 10-1mm.
A Vernier callipers consists of a rectangular steel bars graduated in inches on one edge and in centimeter on the other edge this is know as the main scale. Over this scale slides a small scale called the Vernier scale.
There are two jaws upper and lower, the upper jaws are used to measure the external diameter of rods, tubes etc.it has also a thin rectangular rod on back, which is used to measure depth of vessels.
Vernier constant
The difference between one main scale division and Vernier scale division is called Vernier constant . usually when the jaws are closed, the zero of the main scale concides with the zero of the Vernier scale, then there is no error if this is not so then the caliper have a zero error. There are two types of zero error.
Positive error 2. Negative error
Zero Error
Positive Error
If zero line of Vernier scale lies ahead or on right side of zero line of main scale, then zero will be positive. In order to find the value, observe the number of division on veriner scale which coincides with any main scale division on veriner scale which coincides with any main scale division and this devision is multiplied by least count, say, 4th division of v. coincides with any main scale division then.
Zero error = +4 x L.C
= +4 x 0.01cm
=0.04cm
Zero correction = 0.04cm
Negative Error
If zero line of Vernier scale lies behind OR on left side of zero line of main scale, then error will be negative. In order to find its value, observe number of division of Vernier scale which coincides with scale is coinciding with any main scale division,
Subtract it from 10 and result is multiplied by least count, say, 4th division of v.
Zero error = -(10 – 4)x L.C.
= -6x 0.01 cm
= -0.06cm
Zero correcton =+0.06cm
Procedure
Find least count or Vernier constant of Vernier constant of Vernier callipers. Then find zero error.
Now put the given cylinder lengthwise into the lower jaws and tight the screw of Vernier scale so that the jaws remain fixed. Observe the main scale division just to the left of zero line of Vernier scale div. coincides with any main scale division, n. multiply this no. by least count and then added to main scale reading R. This will give length of cylinder.
Similarly find diameter and then radius of cylinder. Finally calculate volume by using formula.
V = πr2l