# Recent questions tagged transmission

Explain following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).

A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient? A) 0.69 B) 1.69 C) 6.9 D) 16.9

In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

Stability of a transmission line can be increased by

The sag of a transmission line is least affected by (A) Self weight of the conductor. (B) Temperature of the surrounding air. (C) Current through the conductor. (D) Ice deposited on the conductor.

The voltage of transmission can be regulated by  (A) Use of tap changing transformers (B) Switching in shunt capacitors at the receiving end during heavy loads (C) Use of capacitors to neutralize the effect of series reactance (D) Any of the above methods

In a transmission line if booster transformers are to be used, preferred location will be  (A) At the receiving end (B) At the sending end (C) At the intermediate point (D) Anywhere in the line

The permissible voltage variation in transmission and distribution system is:  (A) ± 0.1% (B) ± 1% (C) ±10% (D) ± 25%

In case the height of transmission tower is increased, which of the following parameter is likely to change?  (A) Resistance (B) Inductance (C) Capacitance (D) None of the above

If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.  (A) 11 kV (B) 33 kV (C) 66 kV (D) 132 kV

A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of

The purpose of guard ring in transmission lines is to  (1) reduce the earth capacitance of the lowest unit. (2) increase the earth capacitance of the lowest unit. (3) reduce the transmission lines losses. (4) reduce the reactance of the line

For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is

A transmission line of 200 km has a certain A, B, C and D parameters. If the length is reduced to 60 km

Series capacitive compensation in EHV transmission line is used to

Skin effect is absent in which of the following transmission systems? A) Extra High Voltage (EHV) AC B) High Voltage Direct Current (HVDC) C) Both A and B D) None of these

In voltage source converter based HVDC transmission system the active power is controlled by changing (A) phase angle of the converter ac input voltage (B) supply frequency of the converter ac input voltage (C) magnitude of the converter ac input voltage (D) DC voltage at the inverter terminals

The power flow problem mathematical model for a linear transmission network (A) is non-linear (B) is linear (C) considers time variation of generation (D) does not consider tap-changing transformers

Corona loss in transmission lines can be reduced by (A) using small diameter conductors (B) using bundled conductors (C) using less spacing between conductors (D) increasing the transmission line voltage

The sending end and receiving end voltages of a three-phase transmission line are 10 kV/ph and 9.5 kV/ph, respectively. If the resistance drop is 150 V/ph and receiving end power factor is 0.8, the sending end power factor is (A) 0.745 lagging (B) 0.775 lagging (C) 0.8 lagging (D) 0.85 lagging

Precise control of reactive current flow entering the transmission and distribution systems can be minimized by using (A) synchronous condenser (B) static VAR capacitor (C) capacitor bank (D) thyristor switched reactor in parallel with capacitor

If a 5-bus test system contains 6 transmission lines and one transformer, how many non-zero elements are there in the system Y-bus ? (A) 25 (B) 12 (C) 11 (D) 19

Transmission efficiency of a transmission line increases with the

The standard for long distance analog signal transmission in process control industry is (A) 4-20 mV (B) 0-20 mA (C) 4-20 mA (D) 0-5 V

Why is voltage increases before transmission?

What is meant by extra high voltage transmission?

What is the job of a servo in a transmission?

What are the losses in a transmission line?

Why high voltage is used in power transmission?

What are the advantages of high voltage transmission?

Why transmission voltages are high?

What is electric power generation transmission and distribution?

How many insulator disc used for 33 kV transmission voltage line?