Underground service conductors shall have [Fill-in-the-blank]. A)adequate mechanical strength. B)sufficient ampacity for the loads calculated. C)none of these. D)adequate mechanical strength and sufficient ampacity for the loads calculated.

b) A fault occurs at bus 3 of the network shown in Figure Q4. Pre-fault nodal voltages throughout the network are of 1 p.u. and the impedance of the electric arc is neglected. Sequence impedance parameters of the generator, transmission lines, transformer and load are given in Figure Q4. V₁ = 120° p.u. V₂ = 120° p.u. V₂ = 1/0° p.u. V₂= 120° p.u. jXj0.1 p.u. JX2) 0.1 p.u. jX0j0.15 p.u. jXn-j0.2 p.u. 1 JX(2)-j0.2 p.u. 2 jX)=j0.25 p.u. JX20-10.15 p.u. jXa(z)-j0.2 p.u. 4 jX2(0)=j0.2 p.u. jXT(1) j0.1 p.u. jXT(2)=j0.15 p.u. jXT(0)=j0.1 p.u. Figure Q4. Circuit for problem 4b). = jXj0.1 p.u. j0.1 p.u. - JX(2) JXL(0) 10.1 p.u. = (i) Assuming a balanced excitation, draw the positive, negative and zero sequence Thévenin equivalent circuits as seen from bus 3. (ii) Determine the positive sequence fault current for the case when a three- phase-to-ground fault occurs at bus 3 of the network. (iii) Determine the short-circuit fault current for the case when a one-phase- to-ground fault occurs at bus…

A cable is tested by loss of charge Method using a Ballistic galvanometer with following results : Discharged immediately after electrification deflection 200 divisions. Discharged after 30 second and after electrification (i) Deflection 126 divisions (ii) When in parallel with a resistance of 10 V deflection 100 divisions. Calculate the insulation resistance of the cable.

Calculate the number of turns and the cross section of a conductor for a 300 kVA, 66000/400 volts, 50 Hz, single pahse core type transformer use 1.6 A/mm^2 as current density, 0.070 Wb as maximum flux.

G1=2 G2=4 G3=2 G4=7 G5=2 G6=1 G7=2

The voltage drop percentage for a panel feeder with a no continuous load of 180A, using 3/0 THWN copper conductors at 480V, three-phase, and a length of 248' is

3.a. There may be installations where grounded conductors of different systems are installed within the sameraceway, cable, or box. In these cases, it's imperative that the system-grounded conductors remainA. spliced.B. disconnected.C. separated.D. buried.3.b. In dwelling units, the maximum allowable voltage between conductors that supply lighting fixtures isA. 220 V.B. 120 V.C. 115 V.D. 110 V.

When one of the system conductors is grounded at the transformer, the other system conductors rise to a specific voltage above ground. Select one: TRUE FALSE