# Define zero circle. How it is found out?

Define zero circle. How it is found out?

Zero circle or circle of correction is defined as circle round the circumference of which if tracing point is moved, wheel will simply slide(without rotation) on the paper without any change in reading.

There are three methods of finding area of zero circle.

Method-I To find area of zero circle by using formula.

Area of zero circle =

Where, L= length of tracing arm from hinge to tracing point.

L1=distance from hinge to wheel.

R= length of anchor arm from hinge to anchor point.

+ve sign:- When wheel is placed beyond hinge away from tracing point

-ve sign:- When wheel is placed between hinge and tracing point.

Method-II To find area of zero circle by using planimeter.

i) Measure area of figure with anchor point outside of the figure.

ii) Measure area of figure with anchor point inside of the figure.

iii) Equate two results to find area of zero circle.

Method-III When constants M and C are known.

Area of zero circle = M × C

Where M= multiplying constant.

## Related questions

Description : Define zero circle.

Last Answer : For a mechanical or polar planimeter, when the tracing point moves along a circle without rotation of the wheel i.e. when the wheel just slides without any change in reading, the circle is known as the zero circle.

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Last Answer : Zero Circle - It is the circle formed due to sliding of wheel of mechanical planimeter without changing the reading of circular measuring disc. It is unmeasured circular area on drawing sheet due to non-rotation of counter disc.

Description : What is meant by zero circle? State the advantages of digital planimeter over polar planimeter.

Last Answer : Zero circle:- When the tracing point is moved along a circle without rotation of the wheel i.e. when the wheel slides without any change in reading ,the circle is known as the zero circle or ... are required for area. 3) It gives more accurate reading 4) Less time required for measurement

Description : Give the simplest method of finding the area of zero of a zero circle from manufacturers table.

Last Answer : The area of zero circle can be find out simply by using following formula. A = M x C Where, A = Area of zero circle  M = Multiplier or multiplying constant provided in manufacturers table C = Constant of planimeter provide in manufacturers table

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Description : Define Swinging & Transiting

Last Answer : Swinging: It is the process of turning the telescope in horizontal plane about its vertical axis. Transiting: It is the process of turning the telescope through 180° in a vertical plane about its horizontal axis

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Last Answer : Grade contour :- It is the contour established on a specific grade or gradient along the hill side. OR The line joining the points of equal grade or gradient is called as grade contour.

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Last Answer : Transiting is the method of turning the telescope about its horizontal axis in vertical plane through 180ᴼ.

Description : Define the term interpolation of contours.

Last Answer : Interpolation of contours is the process of locating the required contours proportionately between the plotted reduced levels on sheet.

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Last Answer : The angle subtended at the centre of the circle by a chord of standard length of 30m is known as degree of curve.

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Last Answer : It the process of turning the telescope in horizontal plane about vertical axis.

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