Answer to Question 6

Back

(a) Resistance in the cable = 800 m 0.045 W m-1 = 36 W

(b) P = V2/R  R = V2/P = 2302 3000 W = 17.7 W

(c) Rtot = 36 W + 18 W = 54 W I = V/R = 230 V 54 W = 4.26 A

(d) V = IR = 4.26 A 17.7 W = 75 V.  The machine would not work at all.

(e) The new contractor would install a step up transformer, a high voltage transmission line, and a step-down transformer.  The energy loss would be much less.