1. Find the most economical size of a single core-working
cable core working on a 132 kV, 3phase system, The
maximum permissible stress in the dielectric is not exceed
40 kV/cm.
3. A single-core cable has a conductor diameter of 1 cm and
insulation thickness of 0.4 cm. If the specific resistance of
insulation is 5x10^14 ohm-cm. Calculate the insulation
resistance for a 2km length of cable.
2. A hydroelectric station has a generator efficiency of 86%
and a turbine efficiecy of 92%. The effective head of water is
125 m and a reservoir of 75 x 25 meters dimension.
Calculate the time needed to deliver a load of 4 MW.
4. A hydroelectric power plant is to be constructed. The place
has an annual rainfall of 190 cm. The available catchment
area is 250 sq. km with an available head of 30 meters. On
the average, only 85% of the rainfall can be collected in 70%
of the impounded water is available for power. Assuming
the turbine and generator efficiency is 80% and 92%
respectively, what will be the average power generated.
5. Mark's falls located at Sison, Pangasinan with a height of 100 meters, discharges at a rate of 2.5 m^3/s. NGCP has constructed a hydro plant
below the falls. If the turbine efficiency is 70% and generator efficiency is 90%. Calculate the Energy used in 1 year, if the discarge rate is
constant throughout the year.
7. A 33 kV single-core cable has a conductor diameter of 10 mm
and a sheath of inside diameter 4cm. Find the maximum and
minimum stress in the insulation....
8. A single core cable for use on 11 KV, 50 Hz system has a
conductor area of 0.645cm² and internal diameter of sheath is 0
.0218 m. The permittivity of the dielectric used in the cable is 3.5.
Find the maximum electrostatic stress in the cable.
9. Mark's falls located at Sison, Pangasinan with a height of 100
meters, discharges at a rate of 2.5 m^3/s. NGCP has constructed
a hydro plant below the falls. If the turbine efficiency is 70% and
generator efficiency is 90%. Calculate the Energy used in 1 year, if
the discarge rate is constant throughout the year.
10. A ten- year investigation of rivers potential gave an average
water flow of 25 cm per second at the bottom and 90 cm per
second at the surface. The average cross section at the same
location is 80 sq. m. What is the average flow rate in cubic meter
per hour?
11. A hydroelectric plant generates 100 MW at an available head
of 200 m and efficiency of generator and turbine of 75% and
80% respectively. What quantity of water in gallon per minute
is required....
12. A hydroelectric station has a turbine efficiency of 86% and a
generator efficiency of 92%. The effective head of water is 150 m.
Calculate the volume of water in liter per seconds used when
delivering a load of 40 MW for 6 hours
9. A hydroelectric station has a turbine efficiency of 86% and a
generator efficiency of 92%. The effective head of water is 150 .m.
Calculate the volume of water used when delivering a load of 40
MW for 6 hours.
dielectric loss