For a uniformly distributed load on a distribution feeder, show that the total voltage drop along the full length of the line can be represented by the expression Is.z(l/2) where Isis the rms current at the sending end and z is the impedance per unit length. l is the total length of the line. Also, a line loaded with uniformly increasing load show that the above voltage drop could be represented as Is.z(2l/3). An equilateral triangle-shaped urban residential area shown in figure 02 is to be fed with a distribution transformer located at the center of the area. Three main feeders will run along the roadways at an angle 1200 to each other as shown in thick lines. Five lateral feeders connected to each main feeder run parallel to each side of the triangle. The arrangement of the housing scheme is expected to impose an area load density of 1 MW/km2. The operating voltage is 400 V, three-phase, four-wire type.If the impedance per unit length of a lateral is twice the impedance per unit length of the main feeder, calculate the impedance per unit length of the main feeder, such that the voltage drop anywhere in the residential area will be within 2.5% of the nominal voltage. [Hint: Assume that the loads on the laterals are uniformly distributed along the line]

Customers 1 km Transformer Customers Main Feeders Figure 02 50 Laterals