Physics
When a screw gauge of least count 0.01 mm is used to measure the diameter of a wire, the reading on the sleeve is found to be 1 mm and the reading on the thimble is found to be 27 divisions.
What is the diameter of the wire in cm?
If the zero error is +0.005 cm, what is the correct diameter?
Answer
As we know,
Diameter of the wire = main scale reading + circular scale reading [Equation 1]
and
Reading on thimble = p x L.C. [Equation 2]
Given,
p = 27
L.C. = 0.01 mm = 0.001 cm
Substituting the values in the Equation 2 we get,
reading on thimble = 27 x 0.001 = 0.027 cm
Hence, reading on thimble = 0.027 cm and reading on sleeve = 1 mm = 0.1 cm
Using Equation 1 we get,
Diameter of the wire = 0.1 cm + 0.027 cm = 0.127 cm
Hence, the diameter of the wire is 0.127 cm.
(ii) As we know,
Correct reading = observed reading - zero error
Given,
Zero error = + 0.005 cm
Substituting the value of zero error in the formula above we get,
Correct reading = 0.127 cm - 0.005 cm = 0.122 cm
Hence, the correct diameter of the wire is 0.122 cm
Related Questions
The thimble of a screw gauge has 50 divisions. The spindle advances 1 mm when the screw is turned through two revolutions.
(i) What is the pitch of the screw gauge?
(ii) What is the least count of the screw gauge?
The pitch of a screw gauge is 1 mm and its circular scale has 100 divisions. In measurement of the diameter of a wire, the main scale reads 2 mm and 45th mark on circular scale coincides with the base line.
Find —
- The least count, and
- The diameter of the wire
A screw gauge has 50 divisions on its circular scale and its screw moves by 1 mm on turning it by two rotations. When the flat end of the screw is in contact with the stud, the zero of circular scale lies below the base line and 4th division of circular scale is in line with the base line.
Find —
(i) the pitch,
(ii) the least count and
(iii) the zero error, of the screw gauge.
Figure below shows the reading obtained while measuring the diameter of a wire with a screw gauge. The screw advances by 1 division on main scale when circular head is rotated once.
Find —
(i) pitch of the screw gauge,
(ii) least count of the screw gauge, and
(iii) the diameter of the wire.