T&D Quiz Unit 2

The length of a transmission line is 100km and the line voltage is 66kv. The line is considered to be

• Short

• Medium

• Long

• Very long

The sending end voltage of a transmission line is 150KV and the receiving end voltage is 100KV. The voltage regulation is

• 20%

• 40%

• 50%

• 100%

The transmission efficiency for a short transmission line delivering 50MW whose sending end voltage is 110KV, sending end pf is 0.9 and receiving end current is 280A is

• 90%

• 94%

• 96%

• 98%

Considering ABCD parameters for a transmission line, for a symmetrical network

• A=B

• A=C

• B=C

• A=D

Considering ABCD parameters for a transmission line, for a reciprocal network,

• AB-CD=0

• AD-BC=1

• AB-CD=1

• AC-BD=1

The characteristic impedance of a transmission line is given by

• Sqrt(z/y)

• Sqrt(z.y)

• Sqrt(y/z)

• Sqrt(1/yz)

The propagation constant of a transmission line is given by

• Sqrt(z/y)

• Sqrt(z.y)

• Sqrt(y/z)

• Sqrt(1/yz)

The surge impedance loading of a line is the power delivered by a line to a load impedance

• L=Sqrt(R/C)

• R=Sqrt(L/C)

• L=Sqrt(RC)

• R=Sqrt(LC)

The supply voltage in diagram shown is

• 210V

• 70V

• 50V

• 230V

Ferranti effect on long overhead lines is experienced when it is

• Lightly loaded

• On full load at unity pf

• On full load at 0.8pf lag

• In all these cases