What is zero, positive and negative error in a screw gauge? Physics practical

Table of contents

ZERO ERRORS IN A SCREW GAUGE

To find the zero errors of any screw gauge, the thimble is turned with the objective that the spindle progresses toward the Anvil.

At first the screw of the Circular/Head scale is gone to connect with the Anvil, so the level completion (level finish) of the screw contacts the Anvil and further it is checked by turning the ratchet.

SCREW GAUGE IMAGE

NO ZERO ERROR

NO ZERO ERROR IMAGE

POSITIVE ZERO ERROR

In case zero of the Circular/Head scale is under the reference line then the zero error should be positive.

Exactly when the zero error is positive, the contrasting zero correction is negative and this value will be deducted from the measured value.

POSITIVE ZERO ERROR -IMAGE

For example, the second division of the Circular/Head scale concurs with the zero of the pitch/main scale. For this present circumstance the zero of the Circular/Head scale is under the reference line then the zero error should be positive that is +0.02 mm and the zero correction is negative that is – 0.02 mm which is to be deducted from the measured value.

ALITER

The second division of the Circular/Head scale agrees with the zero of the main/pitch scale. Here the reference focuses are taken as (0, 100). The subsequent division close to the 0 of the reference focuses.

How to correct it to zero? It is basically by removing 2 from the coincidence second division. Then the zero correction(adjustment) is negative and the zero error is positive.

Least count of the screw gauge is 0.01 mm, thus the zero correction and zero error are – 0.02 mm and +0.02 mm separately.

NEGATIVE ZERO ERROR

If zero of the Head/Circular scale is above the reference line then the error should be negative. Exactly when the error is negative, the looking at zero correction in the device is positive and this value will be added to the measured value.

NEGATIVE ZERO ERROR- IMAGE

For example, the 97th division of the Circular/Head scale corresponds with the zero of the pitch/main scale. For this present circumstance the zero of the head scale/circular scale is above the reference line then the zero error should be negative that is – 0.03 mm and the zero correction is positive that is + 0.03 mm which is to be added to the measured value.

ALITER

The 97th division of the Circular/Head scale corresponds with the zero of the main/pitch scale. Here the reference focuses are taken as (0, 100). The 97th division close to the 100 of the reference focus.

How to correct it to hundred? It is fundamentally by adding 3 from the incident 97th division. Then, at that point, the zero correction/adjustment is positive and the corresponding error is negative.

Least count of the screw gauge is 0.01 mm, consequently the zero correction and zero error are +0.03 mm and – 0.03 mm independently.

HOW TO MINIMIZE ERRORS IN SCREW GAUGE?

• Select a screw gauge that is in good condition.
• Ensure that screw gauge is clean and free of dirt.
• While taking the measurement, hold the screw gauge firmly and steadily.
• Avoid using too much force while rotating the screw.
• For accurate measurement take multiple reading and take average out of it.

CONCLUSION

Zero error of a screw gauge is a systematic error that can be positive, negative.The positive, negative errors are mentioned above.The zero error of the screw gauge can be caused by number of factors.The screw gauge errors are mainly due to wear and tear of screw, anvil and other repeated usage of screw gauge parts. The zero error of the screw gauge can be corrected by subtracting the zero error from the measured value.Did you ever check these errors in your school physics laboratory?

QUESTIONS

• What is the source of error in screw gauge?
• How do you know if a screw gauge is zero error?
• Why do we use zero correction?

HOW BANKING OF ROAD WILL HELP THE VEHICLE TO TRAVEL ALONG A CIRCULAR PATH?

INTRODUCTION

The term ‘banking of roads’ refers to an engineering approach that allows vehicles to drive in a circular path.To reduce sliding and accidents, the exterior edge of the road is raised above the level of the inner edge.Banking of roads is used to plan and build safe and efficient highways, motorways, and other roadways.The slope’s purpose is to create centripetal force, which lets the vehicle to safely handle turns at high speeds.Roads that are correctly banked lower the chance of accidents, reduce vehicle wear and tear, and increase traffic flow.To guarantee that roads are safe and efficient for all sorts of vehicles, this strategy demands careful design and implementation.

BANKING OF ROADS

To abstain from sliding, the external edge of the road is raised over the level of the inward edge.Centripetal force, which is acting towards the focal point of the circle is extremely fundamental for the vehicle to go along the roundabout track.

CENTRIPETAL FORCE

IN THE EVENT THAT THE CENTRIPETAL FORCE IS PROVIDED BY FRICTION ONLY

IN THE EVENT THAT THE CENTRIPETAL FORCE IS PROVIDED BY BANKING OF ROADS ONLY

IN THE EVENT THAT THE CENTRIPETAL FORCE IS PROVIDED BY BOTH FRICTION AND BANKING OF ROADS

Consider the vehicle goes along a round tracks which is harsh and banked.In this case, both the friction and normal reaction contribute towards the centripetal force. Three forces that might follow up on the vehicle are

• The first is the force which is the weight (mg) of the vehicle acting vertically downwards.
• The subsequent force is the typical (Normal) reaction(N) which is perpendicular to the road and
• The third force is the frictional force and the course wherein the frictional force acts rely upon the speed of the vehicle.

AT THE POINT WHEN THE VEHICLE IS AT REST

AT THE POINT WHEN THE VEHICLE IS MOVING WITH A SMALL SPEED:

AT THE POINT WHEN THE VEHICLE IS MOVING WITH A LARGE SPEED

GREATEST VELOCITY FOR THE VEHICLE

CONCLUSION

Banking of road is needed at the turning of a road so that to choose the greatest possible speed of the vehicle, in order to stay away from skidding.and additionally the security of the vehicle moving. Did you at any point really take a look at the most extreme conceivable speed of your vehicle on a banked road?