Question

when is A vernier calliper said to be free from the zero error ? ​

Answer 1

When the jaws of the vernier calliper are brought together then if the zero Mark of the vernier scale coincides with the zero Mark of the main scale then the vernier calliper is said to be free from zero error....

Answer 2

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=> When zero of main scale doesn't coincides with zero of vernier scale, then the error is said to zero error.

When zero of main scale doesn't coincides with zero of vernier scale, then the error is said to zero error.When zero of main scale lies towards right side zero of vernier scale without placing any object, then the error is said to be positive zero error and correction is said be negative.

Activity to full information about this topic :>

First close the jaws of the vernier callipers and note down the zero error if any. Then put the object to be measured inside the jaws of a vernier scale, then note down the main scale reading, which is the reading in the main scale corresponding to the zeroth mark in the vernier scale and note it down. Now, take a magnifying glass and find the mark on vernier scale exactly coinciding with any of the main scale. Note the number of the mark coinciding, this is known as vernier scale reading. Multiply the vernier scale reading with least count of the callipers and add with the main scale reading to get the accurate reading. If zero error is there adjust it accordingly and you get the final form of the reading. Least count is the minimum measurement that can be made by a measuring device.

Least count of a vernier callipers = minimum measurement on main scale / total number of divisions on vernier scale.