Page 72 - WCS - Electrical
P. 72

⎛ 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
   67   68   69   70   71   72   73   74   75   76   77