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 0for 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.

788

---

In tower foundation, on the time of 3 mtr pit RCC casting if water and mud is their surface of PCC then what will be do?

1135

---

How to Extract an icon from a .exe or .dll?

764

---

what is the meaning of Processing Vendor/Employee payments

1546

---

what is the basic construction diffrance between servo motor ans sqiralcage induction motor

1270

---

---

What are the main features of Oracle 8i with context to datawarehouse?

879

---

How to Migrate a project from Delphi 1 or 2 to Delphi 3 ?

769

---

what are the differences between malloc() and calloc() in c language?

1211

---

What is the difference between Requirement type Determination and Schedule line category determination ?

402

---

write a c program thal will find all sequences of length N that produce the sum is Zero, print all possible solutions?

1732

---

Which amount of DMEM and Glutamine should be commaneded ?

1078

---

what is milling and types of milling?what is drilling and types of drilling? what is tapering and their types?

1852

---

what is programmable BIST in today ic design

944

---

What are the KPI that decides the capacity expansion of GGSN/xGW?

1708

---

What does port 3050 resolve to as hexadecimal?

492

---