Page 73 - WCS - Electrical

WORKSHOP CALCULATION & SCIENCE - CITS

Solution:

Circumference of outer circle = 134 cm

2 π R = 134 cm
134
R = = 21.32cm
2π
Circumference of inner circle = 90 cm
2 π r = 90 cm
90
r = = 14.32cm
2π
Distance between the circle = R - r
= 21.32 - 14.32 cm
= 7 cm

Area of circular ring = π (R + r) (R - r) unit²
= π (21.32 + 14.32) (21.32 - 14.32) cm²
22
= x 35.64 x 7 cm²
7
= 784.08 cm²

3 A wire can be bend in the form of a circle of radius 56 cm. If it is bend in a form of a square, find the side.

Given:
Radius of circle = 56 cm
To find:
Side of square = ?

Solution:
Radius of circle = 56 cm
3 A wire can be bend in the form of a circle of radius 56
Circumference of circle = 2 r unit = 2π x 56 cm
Circumference of circle = 2πr unit
3 A wire can be bend in the form of a circle of radius 563 A wire can be bend in the form of a circle of radius 56 = 2πr unit = 2π x 56 cm x 56 cm

= 2
Circumference of circle Circumference of circle = 2πr unit = 2π x 56 cm
cm. If it is bend in a form of a square, find the side. Side of square = = x cm = x cm
cm. If it is bend in a form of a square, find the side.cm. If it is bend in a form of a square, find the side.
cm
Side of square
= x cm
Side of square
Side of square
Given:
Given: Given: Wire can be bend from the form of round to square
Wire can be bend from the form of round to square
Radius of circle Radius of circle = 56 cm Wire can be bend from the form of round to squareWire can be bend from the form of round to square
= 56 cm
= 56 cm
Radius of circle
= circumference of circle= circumference of circle
Perimeter of squarePerimeter of square
= circumference of circle
Perimeter of square
To find: To find: Perimeter of square = circumference of circle
To find:
= 352 cm
4 x a
= 352 cm 4 x a
Side of square
Side of square = ? = ? 4 x a 4 x a = 352 cm = 352 cm
Side of square
= ?
Solution:
Solution: Solution: a = 352 = 88cm
Radius of circle Radius of circle = 56 cm a a = = 4 a =
= 56 cm
= 56 cm
Radius of circle
Sector of Circle
Sector of Circle
Sector of CircleSector of Circle
2 Find the radius of the circle if the angle is 60 and the 0
0 0
2 Find the radius of the circle if the angle is 60 and the2 Find the radius of the circle if the angle is 60 and the
area of a sector of a circle is 144 cm , 2
area of a sector of a circle is 144 cm ,area of a sector of a circle is 144 cm ,
2 2
Given: Given:
Given:
Area of sector of circle (A) = 144 cm
Area of sector of circle (A) = 144 cmArea of sector of circle (A) = 144 cm 2
2 2
Angle of sector of circle θ = 60
0 0
Angle of sector of circle θ = 60Angle of sector of circle θ = 60 0
To find:
To find: To find:
Radius of circle = ?
Radius of circle = ?Radius of circle = ?
θ = Angle of sector of circle
θ = Angle of sector of circleθ = Angle of sector of circle Solution: Solution:
Solution:
l = Arc length
l = Arc length l = Arc length 60
x πr
x πr unit=
Area (A)
2 2

2
r = radius
r = radius r = radius Area (A) = = Area (A) unit 2 2 x πr unit 2
CITS : WCS - Electrical - Exercise 5
Length of Arc  =
Length of Arc  = Length of Arc  = x 2πr unit
x 2πr unit
x 2πr unit

144 = = x x r cm= 2 2 x x r cm 2
144
x 144 x r cm
2 2
2
Perimeter P = 2r +  unit
Perimeter P = 2r +  unitPerimeter P = 2r +  unit
r r 2 2 = 274.91 cm 2 2 = 274.91 cm 2
= 274.91 cmr
2
lr lr lr
x πr unit
Area =
Aπr unit =
2 2
2 2
Area = x πr unit (or)Area = (or) x A 2 2 = (or) unit 2 2 = unit 2 r r = = r = 16.58 cm = 16.58 cm
unit A
= 16.58 cm=

2 2 2
1 Find the perimeter and area of a sector of circle of radius
1 Find the perimeter and area of a sector of circle of radius1 Find the perimeter and area of a sector of circle of radius
3 Find the area of the sector whose angle is 105 , and the3 Find the area of the sector whose angle is 105 , and the
0 0
7 cm and its angle is 120 . 0 3 Find the area of the sector whose angle is 105 , and the 0
7 cm and its angle is 120 .7 cm and its angle is 120 .
0 0
perimeter of sector of circle is 18.6 cm.perimeter of sector of circle is 18.6 cm.
Given: Given: perimeter of sector of circle is 18.6 cm.
Given:
Given:
Angle of sector of circle = 120 0 0 = 120 0 Given: Given:
= 120
Angle of sector of circleAngle of sector of circle
Perimeter of a sector of a circle = 18.6 cm
= 7 cm
Radius
Radius = 7 cmRadius = 7 cm Perimeter of a sector of a circle = 18.6 cmPerimeter of a sector of a circle = 18.6 cm
Angle of sector of circle = 105
Angle of sector of circle = 105Angle of sector of circle = 105
0 0
0
To find:
To find: To find: To find: To find:
To find:
Perimeter = ? , Area = ?
Perimeter = ? , Area = ?Perimeter = ? , Area = ?
Area = ?
Solution:
Solution: Solution: Area = ? Area = ?
Solution: Solution:
Solution:
Length of arc ()
Length of arc () = = x 2πr unit x 2πr unit
Length of arc (
x 2πr unit) =
Length of Arc ()
Length of Arc () = = x 2 x 2πr unit
Length of Arc (πr unit
x 2πr unit) =
= = x 2 x x 7 cm x 2 x x 7 cm
x 2 x
x 7 cm=
 = = x 2 x  = x r x 2 x x r

x 2 x
x r
= 14.67 cm
= 14.67 cm = 14.67 cm
= 1.83r = 1.83r
= 1.83r
Perimeter = 2r +unit
Perimeter = 2r +unitPerimeter = 2r +unit
=  + 2r unit
Perimeter (P)
Perimeter (P) Perimeter (P) =  + 2r unit
=  + 2r unit
= 2 x 7 + 14.67 cm
= 2 x 7 + 14.67 cm= 2 x 7 + 14.67 cm
= 1.83r + 2r18.6
18.6
= 28.67 cm
= 28.67 cm = 28.67 cm 18.6 = 1.83r + 2r = 1.83r + 2r
3.83r = 18.6 cm3.83r = 18.6 cm
= 18.6 cm
3.83r
Area = = Area x πr unit 2 2 x πr unit 2

Area
x πr unit=
2 2
2
r r = = = 4.86 cm = = 4.86 cm
= 4.86 cm
r
Area = x x 7 cm = 51.33 cm 2 2 2 2
2 2
x 7 cm = 51.33 cm
x 7 cm = 51.33 cmx
Area =
x Area =

WCS - Electrician & Wireman : (NSQF - Revised 2022) - 1 Year : Exercise 1.7.26
WCS - Electrician & Wireman : (NSQF - Revised 2022) - 1
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WCS - Electrician & Wireman : (NSQF - Revised 2022) - 1 Year : Exercise 1.7.26 Year : Exercise 1.7.26 67
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