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8. A 500 V, 2-core feeder 0.8 km long is required to supply a constant load of 100 kW. The cost of the cable including installation charges is Rs (6 a + 1.3) per metre where a is the cross-sectional area of each conductor in cm². Interest and depreciation total 10%. Determine the most economical size. Cost of energy is 2P per unit. Specific resistance of copper is 1.75 x 10?? ? per cm² cross-sectional area and 1 cm long. [B.T.E. A.P. Power Systems II April/May 1995] [Ans 2.022 cm²] 9. A 2-core, 11 kV cable is to supply 1 MW at 0.8 pf lag for 3,000 hours in a year. Capital cost of the cable is Rs (20 + 400 a) per metre where a is the x-sectional area of core in cm². Interest and depreciation total 10% and cost per unit of energy is 15 paise. If the length of the cable is 1 km, calculate the most economical x-section of the conductor. The specific resistance of copper is 1.75 x 10?? ?-cm. [A.M.I.E. Sec B. Power Systems Summer 1993] [Ans 0.2255 cm²] 10. Find the most economical x-section of a 3-core feeder cable 250 m long supplying a load of 80 kW, 0.8 pf (lagging) at 400 V for 4,000 hrs per year. The cost of the cable including installation is Rs (150 a + 250) per metre where a is the x-section of each conductor in cm². Interest and depreciation total 10%. Cost of energy wasted is Rs 1 per unit. The resistance per km of conductor 1 cm² cross-section is 0.173 ?. [A.M.I.E. Sec B. Power Systems Winter 1996]

          8. A 500 V, 2-core feeder 0.8 km long is required to supply a constant load of 100 kW. The cost of the cable including installation charges is Rs (6 a + 1.3) per metre where a is the cross-sectional area of each conductor in cm². Interest and depreciation total 10%. Determine the most economical size. Cost of energy is 2P per unit. Specific resistance of copper is 1.75 x 10?? ? per cm² cross-sectional area and 1 cm long. [B.T.E. A.P. Power Systems II April/May 1995] [Ans 2.022 cm²]

9. A 2-core, 11 kV cable is to supply 1 MW at 0.8 pf lag for 3,000 hours in a year. Capital cost of the cable is Rs (20 + 400 a) per metre where a is the x-sectional area of core in cm². Interest and depreciation total 10% and cost per unit of energy is 15 paise. If the length of the cable is 1 km, calculate the most economical x-section of the conductor. The specific resistance of copper is 1.75 x 10?? ?-cm. [A.M.I.E. Sec B. Power Systems Summer 1993] [Ans 0.2255 cm²]

10. Find the most economical x-section of a 3-core feeder cable 250 m long supplying a load of 80 kW, 0.8 pf (lagging) at 400 V for 4,000 hrs per year. The cost of the cable including installation is Rs (150 a + 250) per metre where a is the x-section of each conductor in cm². Interest and depreciation total 10%. Cost of energy wasted is Rs 1 per unit. The resistance per km of conductor 1 cm² cross-section is 0.173 ?. [A.M.I.E. Sec B. Power Systems Winter 1996]

8. A 500 V, 2-core feeder 0.8 km long is required to supply a constant load of 100 kW. The cost of the cable including installation charges is Rs (6 a + 1.3) per metre where a is the cross-sectional area of each conductor in cm². Interest and depreciation total 10%. Determine the most economical size. Cost of energy is 2P per unit. Specific resistance of copper is 1.75 x 10?? ? per cm² cross-sectional area and 1 cm long. [B.T.E. A.P. Power Systems II April/May 1995] [Ans 2.022 cm²]

9. A 2-core, 11 kV cable is to supply 1 MW at 0.8 pf lag for 3,000 hours in a year. Capital cost of the cable is Rs (20 + 400 a) per metre where a is the x-sectional area of core in cm². Interest and depreciation total 10% and cost per unit of energy is 15 paise. If the length of the cable is 1 km, calculate the most economical x-section of the conductor. The specific resistance of copper is 1.75 x 10?? ?-cm. [A.M.I.E. Sec B. Power Systems Summer 1993] [Ans 0.2255 cm²]

10. Find the most economical x-section of a 3-core feeder cable 250 m long supplying a load of 80 kW, 0.8 pf (lagging) at 400 V for 4,000 hrs per year. The cost of the cable including installation is Rs (150 a + 250) per metre where a is the x-section of each conductor in cm². Interest and depreciation total 10%. Cost of energy wasted is Rs 1 per unit. The resistance per km of conductor 1 cm² cross-section is 0.173 ?. [A.M.I.E. Sec B. Power Systems Winter 1996]

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