A screw gauge gives the following readings when used to measure the diameter of a wire
Main scale reading : 0 mm
Circular scale reading : 52 divisions
Given that 1 mm on main scale corresponds to 100 divisions on the circular scale.
The diameter of the wire from the above data is :
Correct Answer :
0.052 cm
Solution :
To find the diameter of the wire, we need to calculate the least count of the screw gauge and then use the readings to determine the total measurement.
Step 1: Understand the given parameters
Main scale reading (MSR) =
Circular scale reading (CSR) =
Pitch of the screw gauge (the distance corresponding to one full rotation or the smallest division on the main scale) =
Total number of circular scale divisions =
Step 2: Calculate the Least Count (LC) of the screw gauge
The least count is the smallest value that can be measured accurately by the instrument, calculated as:
Substituting the given values:
Step 3: Calculate the measured diameter
The formula for the total reading (diameter) is:
Substituting the values we have:
Step 4: Convert the diameter to centimeters (cm)
Since the options are given in centimeters, we convert millimeters to centimeters by dividing by (since ):
Therefore, the correct diameter of the wire is 0.052 cm.
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