Question

A room has AC run for 5 hours a day at a voltage of 220 V. The wiring of the room consists of Cu of I mm radius and a length of 10 m. Power consumption per day is 10 commercial units. What fraction of it goes in the joule heating in wires ? What would happen if the wiring is made of aluminium of the same dimensions ? IPcu 1.7 x 105 2 m, Pal = 2.7 x 10- Q m] 6.

Answer 1

Answer:

Power consumption =5hour10units=hour2units

                                   =2kw

                                   =2000J/S

So, I=VP

          =2202000

          =9.09A

Power loss in copper wire =IR

                                             =I2APL

Power loss in copper wire =9.09×9.09×17×(10−3)21.7×10−8×10

                                             =4.47J

                                             =20004.47×100%

                                             =0.22%

Power loss in aluminium wire =I2R=I2APL

Power loss in copper wire =9.09×9.09×17×(10−3)22.7×10−8×10

                                             =7.1J

                                             =