hloo guys....
Define leastcount of a screw gauge
Define pitch
What is backlash error? How is it avoided?
What is zero error? How is it determined?
When do you say that the zero error is positive or negative?
What are random errors? How can you minimise them?
What is the use of ratchet in a screw gauge?
Answers
Answer:
Least count=pitch/number of division of thimble.
The quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone is known as Pitch.
In case of micrometre screw gauge the backlash error is the error in which measurement due to backlash of the internal gears.In a pair of machine gears the distance between two space and tooth thickness is called as backlash. Tooth thickness is the distance between two adjacent teeth measured along the pitch circle .
It is a type of error in which an instrument gives a reading when the true reading at that time is zero. For example needle of ammeter failing to return to zero when no current flows through it.
An error in measurement caused by factors which vary from one measurement to another is known as Random errors
Answer:
ever if it is essential to turn the direction of the rotation then do not change the direction abruptly . move the screw still further ,stop there for a while and then rote it in reverse direction.