1

EXPT NO: 1. USE OF VERNIER CALLIPERS

Aim :  To determine volume of solid sphere and measure inner diameter, depth of hollow

cylinder.

Apparatus: Vernier callipers, solid sphere, hollow cylinder.

Diagram:

Vernier Calliper

Vernier Calliper zero error

Formula:        Radius of Sphere       = r

Procedure:

I) To find the least count :

·         Initially find the  smallest division on the main scale of vernier calliper

·         Note down the total number of divisions on the vernier scale.

·         With the help of the formula calculate the least count of the vernier calliper.

To find the zero error:

·         Bring the two jaws of vernier calliper in contact then Observe and study conditions.

·         No Zero Error :If zero reading  of main scale coincides with  zero division of vernier scale. There is no zero error.

·         + Ve Zero Error :If zero division  of vernier scale is on right (ahead) of zero reading of main scale and if mth division of vernier scale coincides with some reading  on main scale then the .                                        Zero error = +m x L.C.

·         -Ve Zero Error : If zero  division of vernier scale is on left (behind) of zero reading of main scale and if mth division of vernier scale coincides with some reading on main scale.

Zero error = (N-m) L.C.

III)   To determine the volume of sphere

·         Hold the given solid sphere between the lower jaws of vernier calliper as shown.

·         Note the position of the zero mark of vernier scale on the main scale. Let this main scale reading be 'A'.

·         Note the vernier division (B) that coincides with some division on main scale.

·         Then calculate the total reading (C) with formula C = A + (B x L.C.)

·         Take at least three independent readings for different positions of the sphere.

·         Apply correction according to zero error (C + Z) and find the mean value of diameter (D).

·         Hence radius of sphere  

IV)   Find the inner diameter and depth of hollow cylinder in similar manner.

V)     Calculate the volume of sphere.

Observations:

                        Smallest division on main scale                    =……………..cm

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

 Least count of vernier callipers. =L.C.       =…………….cm

           

Object	Obs No	Dimension	Main Scale reading A cm	Vernier Scale reading B	Total reading C=A+(BxL.C)	Corrected reading T=C+Z cm	Mean reading cm
Sphere	01	Diameter
	02
	03
Cylinder	01	Inner Diameter
	02
	03
Cylinder	01	Depth
	02
	03

Calculations :

Least Count :

Value Log 4 Log4=………….. p=3.14 Log3.14=………… R= Log(         )=…….. R= Log(         )=…….. R= Log(         )=…….. + 3 Log  =………….. Y  =      -  V=  Antilog Y V=

Result :

i)          Volume of the sphere                        =……………cm³

ii)         Inner diameter of hollow cylinder   =……………cm

iii)        Depth of hollow cylinder                  =……………cm

Precautions :

i)          While taking reading, do not press the jaws too hard.

ii)         The different readings for diameter of an object should be taken at different positions.

iii)        While recording reading, eye should exactly be perpendicular to vernier scale.

J K L