Question

Q10. Transmission lines transport electricity for a long distance through cables. i. Distinguish between overhead and underground cables. (4 marks) ii. Discuss the differences between transmission and distribution lines. (4 marks)

Answer 1

One Disting wish between overhead and under goound cables; under ground overo head cable O more expensive O less expensive. is & Installation is not easy. because it require @ Installation Very easy compared to underground high digging ☺ Heat dissipation is limited the layers of insulation and protection Such as com cromouring by ② Heat is realeased to the surrounding and auto- -matic Cooling is provided by the air o Kerger Conductor Size Smaller conductor size. 5 swited for 33 kV Voltage 6 suited for high Voltage Power toonsfer. not 6 to deled and repair Easy fault 6 easy to detect and repair the fault .

(ii) difference between transmission and distribution line :- a Transmissim line tooms for the Power from a power plent to the Substations where as distribution line Caries power from substation to the load (consumer's) ond. 6 Distribution time are thin as compared to the transmissim line. Conducts Ensent at less than 66kv. © Distribution line or more than but dransmission works for 66 kv line 66 kV. d The safe value for transmission is about 230 V and the safe value for transmission is about likv. Distribution system System requires a single phase Supply but Poansmissim line camer power or 30 Suphly at 36 Phase ) Suphly system.