Year 2024

Week # 2 Quiz 5

Q1. What is the maximum length of a 1-phase transmission line having copper conductor of 0.7\(cm^2\) cross-section, over which 180 kW at unity power factor and at 3600 V are to be delivered? The efficiency of transmission is 90% (Take specific resistance as 1.4 \(\mu\)\(\Omega\) cm.)

Q2. The inductance of transmission line is 1mH/km. If the spacing between conductors is made double the new inductance of line will be approx.

Q3. The size of jacobian matrix of a 13 bus power system with 5 voltage controlled buses and a slack bus is

Q4. Which type of relay is less affected by power surges?

Q5. The time-current graph of a fuse

Q6. For a relay, whose relay setting is 50% and the CT ratio is 500/5. What will be the value of fault current when the plug setting multiplier is 8.

Q7. Surge impedance loading of a transmission line can be increased by

Q8. A 30 MVA, 33 kV transformer has a per unit impedance of 0.75. The per unit impedance at a new base 60 MVA and 11 kV is

Q9. Statement 1: The admittance matrix will be singular for a power system network which is not having any shunt element.
Statement 2: The admittance matrix will be non-singular for a power system network which is not having any shunt element
Which of the aforementioned statements is true?

Q10. The following sequence currents were recorded in a power system under a fault condition: \(I_{positive} = j1.653 \: p.u. , I_{negative} = -j0.5 \: p.u. \: and \: I_{zero} = -j 1.153 \: p.u.\). The fault is