The reference or index line can be divided into some convenient units or divisions and it is called
Head scale
Pitch scale
Least count
None of these
Equation for Least Count ,L.C =
P / N
PN
N/P
PN2
The head of a screw gauge is divided in to 50 divisions. It advances 1 mm when screw is turned through 2 rotations. Find the pitch of the screw and least count of the screw gauge.
0.5 mm, 0.001 mm
0.05 mm,0.01 mm
5 mm, 0.1 mm
0.5 mm, 0.01 mm
The value of the head scale division which just coincides with the reference line is observed as
Head Scale Reading
Ordinary Scale Reading
Pitch Scale Reading
Corrected Head Scale Reading
For positive zero error, the correction and error are :
-ve,+ve
+ve,-ve
+ve, +ve
-ve, -ve
The value of Least count ,L.C =
1mm
0.001 cm
0.01 cm
If the zeroth division of the head scale is above the index line ,the error is said to be
Negative
Positive
Neutral
Find the Least count of screw gauge whose head scale is divided into 200 divisions and pitch of the screw is 1 mm?
0.05 mm
0.05 cm
0.0005 cm
0.005 cm
While measuring the diameter of a lead shot using a screw gauge,the reading on the pitch scale is found to be 7.5 mm and that on the head scale is 48. If the least count is 0.01 mm,the diameter of the lead shot is
0.798 mm
7.98 mm
0.0798 mm
0.00798 mm
If the zeroth division of the head scale is below the index line ,the error is said to be positive and the correction is
