A power station delivers 750 kW of power at 12,000 V through wires with a total resistance of 3.0 Ohm. How much less power is wasted if the electricity is delivered at 50,000 V rather than 12,000 V?
Two resistors when connected in series to a 120-VV line use
one-fourth the power that is used when they are connected in
parallel.
Part A
If one resistor is 2.6 kΩkΩ , what is the resistance of the
other?
The power supply, the resistors
and the wires can be connected such that the current drawn from the
supply is smaller than the ratio of voltage provided by the power
supply and the sum of all the resistors used.
The power supply, the resistors and the wires can be connected
such that the current drawn from the supply is larger than the
ratio of voltage provided by the power supply and the sum of all
the resistors used.
The power...
A hydro power station is required to deliver 48MW of
power to the national grid from a site where the available head is
16m The alternator efficiency may be taken as 96%.The proposed
rotational speed of the coupled turbo-alternators is 150r/min and
the specific speed of the available turbines is 400. Estimate the
number 9f units required
A factory produces copper wires. A blue mark is placed on a very
long length of copper. The wire is then cut into pieces. The
lengths of different pieces are independent, and the length of each
piece is distributed according to the same PDF fX(x). Let R be
length of the piece including the blue mark. Determine the expected
value of R in each of the following cases.
In each part below, express your answer in terms of μ using...
A 900 MW power station transmits power
at a potential difference of 60, 000 V
a) Find the current.
b) Write down the equation for the resistance in terms of the
resistivity.
c) If the power loss is 110 MW, over the length of the 200 km
power line, find the resistivity of the line, if its cross section
is 9 cm 2.
d) Write down the equation for the magnetic field due to a long
conductor.
e) Find the...
When the tail light of a car is turned on, 0.5 A flows through
the wires. The length of one wire from the battery to the tail
light is 5.0 meters.Estimate how long you think it will take an
electron to travel from the battery to the tail light and how many
electrons flow through the tail in one minute. Thank you!
Given :
14AWG copper wire is used, which has a cross sectional area of
2.1e-6 m^2
2 The...
A solenoid with 2000 turns/meter is connected to a power source
that delivers an increasing current i60t^2 Ampere.The solenoid has
a length of 0.2 m and a radius of 0.05 m.
a.what is the magnetic field as a function of timr inside the
solenoid?
b.Use Faraday's law to find the induced emf caused by this
changing magnetic field.
You are on a factory visit to a plant
for food products. Rushing through the factory, you hear that a
vapor compression cycle with refrigerant HFC-134a as the working
fluid is being used. You see that they use a throttle valve as part
of the system and that one part of the cycle is running at 0.32 MPa
and another part of the cycle is running at 1.6 MPa. If the
compressor is 80% efficient and throttle, condenser, and evaporator...
1. What is the need of a sub-station in the power system ?
2. Why are pole-mounted sub-stations very popular ?
3. Where we erect a terminal sub-station ?
4. Why do we use isolators on both sides of circuit breaker
?
5. What is the utility of instrument transformers in
sub-stations ?