A 40 kva transformer has a core loss of 400W and a full load
copper loss of 800W. What is The proportion of full load at
maxmimum efficiency?
Post New Answer View All Answers
What is polar plot?
What is the previous name of Cox's Bazar
1. A 380 / 220 V r.m.s. 3-phase 4-wire circuit carries loads of 8 + j8.1 ohm; 4 + j4.1 ohm; and 2 +j2.1 ohmin the three phases respectively. The length of the circuit is 100 m, and the resistivity of the phase conductors is 0.0005 Ω/m. The neutral conductor is of the same size as the phase conductors. a) Select a reference angle 0for the first phase. Then write down the three phase voltages in both polar format and complex number format. b) Make appropriate assumptions, and take temperature effects on resistance is insignificant. Calculate the currents in the three phases. (Note: Determine conductor resistance, and apply Kirchhoff’s Voltage Law) Based on the result, suggest a main switch rating for the circuit. c) Show your preferred direction of neutral current in a diagram, and then determine its value. (Note: Apply superposition principle, and Kirchhoff’s Current Law) Use its magnitude to show that in this circuit, the unbalanced load may increase the voltage drop in some of the phases. (Note: Also observe the common volt drip in neutral) State your assumptions, if there are any. d) Suddenly the neutral wire of the circuit is broken. Estimate the new currents in the first phase, i.e. Phase L1. State your assumptions, if there are any.
What happens if we give the supply to the rotor of induction motor and make its terminal shorted?
how to define tell me about self
Name the test signals used in control system
What is meant by coupling capacitor?
How many turns are there in primary winding? (In Transformer)
what is resver in electrical enginnering with answer
In PFI plant one stage capacitor connection is directly connected(with out megnetic contact controll). but why?
What is the working principle of CFL & T5 tube light & 40W tube light with electronic ballast?
what are the disadvantages in GIS over AIS
Why reactors use before incoming of ac vvfd drive?
whats the existence of reactive power and when it arises?
how the testing of protection CT Testing done through Primary injection kit please describe in detail procedure...