# 100 Most Important MCQ Of Transmission and Distribution | Electrical Engineering Multiple choices Question

Ques 1. By which of the following method electric power may be transmitted from one location to another location?

1. UnderGround System
3. Both 1 and 2
4. None of the above
Answer 3. Both 1 & 2

Explanation: Electrical power is generally transmitted by two methods i.e underground transmission and overhead transmission

Ques 2. Which of the following transmission line have more initial cost?

2. Underground transmission
3. Both have almost same initial cost
4. None of the above

Explanation:

• The underground cable can be 2-3 times more expensive than the overhead cable.
• As the voltage level increases the cost of insulation is increased therefore the underground cable is restricted to low and medium voltages.

Ques 3.  Name the cable or conductor which connects the distributor to the consumer terminals.

1. Service Mains
2. Distributor
3. Feeders
4. None of the above

Explanation:

• Service Mains: The service mains conductors form connecting links between distributors and metering points at consumer terminal.
• The area of connection of a sub-main conductor is greater than the service mains.

Ques 4. Which of the following materials are not used for transmission and distribution of electrical power?

1. Copper
2. Aluminium
3. Tungsten
4. Steel

Explanation:

• The resistance of tungsten is very high, more the resistance more the losses, therefore, tungsten is never used for transmission and distribution purposes.

Ques 5.  The usual spans with R.C.C. poles are

1. 40—50 metres
2. 60—100 metres
3. 200 – 300 meters
4. 80 – 150 meters
Answer 4. 80 – 150 meters

Explanation:

## Reinforced concrete pole(R.C.C Pole)

• The Reinforced concrete pole (R.C.C) is usually called as Concrete pole and they are used for system voltage up to 33kV.
• Minimum overall length of R.C.C pole should be six meters.
• The span length of R.C.C is between 80 – 200 meter because they are stronger and more durable.
• They are free from corrosion hence poles have the longer life but these are very bulky in sizes.

Ques 6. Which of the following are the constants of the transmission lines?

1. Inductance
2. Capacitance
3. Resistance
4. Conductance
5. All of the above
Answer 5. All of the Above

Explanation:

## a b c d constants of the transmission line( Primary line constants)

• The line constants are parameters that describe the characteristics of conductive transmission lines.
• The primary line has following constants
• R = Resistance per unit length Ω
• L = Inductance per unit length (Henry) H
• C = Capacitance per unit length (Henry) H
• G = Conductance per unit length ℧
• All these constants are independent of frequency, therefore, they are called as primary constants and these constants are measured by considering both the wires of the transmission lines.
• R and L elements are in series with the line (because they are properties of the conductor) and C and G are elements shunting the line (because they are properties of the dielectric material between the conductors).
• G represents leakage current through the dielectric and in most cables is very small.

Ques 7. The phenomenon of rising in voltage at the receiving end of the open-circuited or lightly loaded line is called as

1. Roman Effect
2. Skin Effect
3. Corona Effect
4. Ferranti Effect

Explanation:

## Ferranti Effect

• The phenomenon of the rise of voltage at receiving-end of an open circuited or lightly loaded transmission line is called as the Ferranti effect.
• The receiving end voltage becomes more than the sending end voltage.
• The Ferranti effect occurs in medium and long transmission lines.
• The Ferranti Effect will be more pronounced the longer the line and the higher the voltage applied.The relative voltage rise is proportional to the square of the line length.
• The Ferranti effect is much more pronounced in underground cables, even in short lengths, because of their high capacitance.

Ques 8. Low tension cables are meant for use up to

1. 1 kV
2. 5 kV
3. 10 kV
4. 33 kV

Explanation: Low voltage cables with a range up to 1 kV are used for energy distribution from the last transformer station to the customer.

Ques 9. The operating voltage of high tension cables is up to

1. 1 – 11 kV
2. 11 – 20 kV
3. 11 – 33 kV
4. above 33 kV
Answer 1. 1 – 11 kV

Explanation:

• High tension cables are used for three-phase medium. These consist of three core belted type cable with separated insulation for each core.
• The paper insulation is provided for high-tension cables.
• The operating voltage of high tension cable is upto 11kV.

Ques 10. The operating voltage of super tension cable is

1. 1 – 11 kV
2. 11 – 33 kV
3. 33 – 66 kV
4. Above 66 kV

Explanation:

• Super tension cables are used upto the voltage level of 33 kV. They are further classified into 3 types
1. H – type or screened cables
2. SL type cables
3. HSL types cables

1. Rishikesh kumar says:

Thank you very much it help me so much

2. lumbini nikose says:

thank u so much… what a great work.. hats off each answer is explained beautfully

3. Jitendra kumar says:

Thanks very much. It is very helpful.

4. Sumithra says:

Good explanation.. Great job

Thanks for appreciation @ Sumithra