Page 72 - WCS - Electrical

⎛ 22

= 6⎜
+ 14

⎛ 22
7
⎝
7
⎝
= 6 x
36
7
= 6 x
7
216
=
216
=
= 30.
786 cm
= 30.86 cm
2 From the figure given below ABCD is a steel plate, a
semi circular plate of radius 50 mm has been prepared
2 From the figure given below ABCD is a steel plate, a
Waste area = Plate area - Area of semi circle
2
r π
by gas cutting. Find the waste area.
semi circular plate of radius 50 mm has been prepared
= lb -
2
r π2
by gas cutting. Find the waste area.
= lb -
Plate length AB
= 100 mm
2
x
22
50
x
50
Plate length AB = 6⎜ 7 36 + 14 ⎞ ⎟ ⎞ ⎠ ⎟ ⎠ Waste area = Plate area - Area of semi circle
= 100 mm
Breadth BC
= 50 mm
= 100 x 50 -
50
22
50
x
x
2
7
x
Breadth BC = 50 mm WORKSHOP CALCULATION & SCIENCE - CITS
= 100 x 50 -
Radius
= 50 mm
Radius = 50 mm = 5000 - 3928.57 7 x 2
= 5000 - 3928.57
= 1071.43 mm
2
= 1071.43 mm 2
Circular ring
Circular ring
Circular ring 2 Find the distance between the boundaries and the area
of the circular ring, if the circumference of two concentric
2 Find the distance between the boundaries and the area
circle are 134 cm and 90 cm.
of the circular ring, if the circumference of two concentric
circle are 134 cm and 90 cm.
Given:
Given:
Circumference of outer circle = 134 cm
Circumference of outer circle = 134 cm
Circumference of inner circle = 90 cm
Circumference of inner circle = 90 cm
R = Outer radius of circular ring To find:
R = Outer radius of circular ring To find:
Distance between the circles = ?
r = Inner radius of circular ring
Distance between the circles = ?
Area of circular ring = π (R - r ) unit 2
2
r = Inner radius of circular ring 2 Area of circular ring = ?
Area of circular ring = ?
or
Area of circular ring = π (R - r ) unit 2 Solution:
2
2
A = π (R + r) (R - r) unit
or 2 Solution:
Circumference of outer circle = 134 cm
A = π (R + r) (R - r) unit 2 Circumference of outer circle = 134 cm
1 Calculate the area of cross section of pipe having
= 134 cm
2 π R
1 Calculate the area of cross section of pipe having outside dia of 17 cm and inside dia of 14 cm.
outside dia of 17 cm and inside dia of 14 cm.
1 Calculate the area of cross section of pipe having 2 π R = 134 cm
Given: outside dia of 17 cm and inside dia of 14 cm. R =
Given:
Given: R =
Outer dia of pipe = 17 cm
Outer dia of pipe = 17 cm
Outer dia of pipe = 17 cm 17 Circumference of inner circle = 90 cm
Outer radius of pipe (R) = 2 = 8.5 cm Circumference of inner circle = 90 cm
= 90 cm
2 π r
Outer radius of pipe (R) =
= 8.5 cm
Outer radius of pipe (R) =
Inner dia of pipe = 14 cm = 8.5 cm 2 π r = 90 cm
Inner dia of pipe = 14 cm
14
Inner dia of pipe = 14 cm r =
Inner radius of pipe (r) = 2 = 7 cm r =
= 7 cm
Inner radius of pipe (r) =
Inner radius of pipe (r) = = 7 cm Distance between the circle = R - r
To find:
To find: Distance between the circle = R - r
= 21.32 - 14.32 cm
Area of cross section of pipe = ?
To find:
Area of cross section of pipe = ? = 21.32 - 14.32 cm
= 7 cm
Area of cross section of pipe = ?
Solution:
Solution: 2 Area of circular ring = 7 cm 2
Solution:
= π (R + r) (R - r) unit
Area of cross section of pipe = π (R + r) (R - r) unit
2
Area of cross section of pipe = π (R + r) (R - r) unit 2 Area of circular ring = π (R + r) (R - r) unit 2
= π (21.32 + 14.32) (21.32 - 14.32) cm
= π (8.5 + 7) (8.5 - 7)
= π (8.5 + 7) (8.5 - 7) = π (21.32 + 14.32) (21.32 - 14.32) cm 2
= x 15.5 x 1.5 cm 2 = x 35.64 x 7 cm 2
= x 15.5 x 1.5 cm 2 = x 35.64 x 7 cm 2
2
= 73 cm 2 = 784.08 cm
= 73 cm 2 = 784.08 cm 2
st
66 WCS - Electrician & Wireman : (NSQF - Revised 2022) - 1 Year : Exercise 1.7.26
WCS - Electrician & Wireman : (NSQF - Revised 2022) - 1 Year : Exercise 1.7.26
2 Find the distance between the boundaries and the area of the circular ring, if the circumference of two concentric
st
66
circle are 134 cm and 90 cm.
Given:
Circumference of outer circle = 134 cm
Circumference of inner circle = 90 cm
To find:
Distance between the circles = ?
Area of circular ring = ?
59
CITS : WCS - Electrical - Exercise 5