Question

Zero error and its determination in screw guage

Answer 1

zero error is the error when the zero of the instrument dosen't coincides with the zero of the graduated mark

in case of screw gauge the zero of circular scale reading  is there which dosent coincides with the zero of main scale reading

now to remove this error while taking first of all you must bring the main scale reading to zero dont care about the circular scale reading

now once you have brought it to zero check reading of circular scale

1.  now two conditions are there either it will give a reading more than zero say 10 or 20 etc whatever you get but it must be below 50

2.  2nd condition is that you will get a reading in negative side that is for example say 90 or 80 but it must be greater than 50 (pls carefully note the difference in two cases i have mentioned)

now for first condition just subtract the extra reading that is 10 or 20 or whatever but below 50 in order to remove zero error after taking reading

now for second case just add the missing reading which will be also like 10 or 20 or etc based on the zero error u will get (if it is 90 then add 10 or if it is 80 then add 20 or etc ) in order to remove the zero error

hope this helps

thx for asking this question it is a very important one

pls mark me as brainliest