TRANSMISSION LINES

Question 1

A metallic conductor system used to transfer electrical energy from one point to another.

Answer 1

transmission line

Question 2

What are the basic kinds of waves based on the direction of signal?

Answer 2

• Incident Waves
• Reflected Waves

Question 3

What type of wave has displacement of the medium parallel to the propagation of the wave?

Answer 3

Longitudinal Wave

Question 4

What type of wave has displacement of the medium perpendicular to the direction of propagation?

Answer 4

Transverse Wave

Question 5

What are the types of transmission lines?

Answer 5

Parallel Wire / Balanced Line
Coaxial Line / Unbalanced Line
Twisted-Pair Cable
Twin Lead or Ribbon Cable

Question 6

Made up of two parallel conductors spaced from one another by a distance of ½ inch up to several inches.

Answer 6

balanced line

Question 7

What is UTP?

Answer 7

Unshielded Twisted Pair

Question 8

What is STP?

Answer 8

Shielded Twisted Pair

Question 9

Consists of a solid center conductor surrounded by a plastic insulator and a tubular braid or shield made of fine wires.coaxial cable

Answer 9

coaxial cable

Question 10

What happens to transmission lines at low frequencies?

Answer 10

They are resistive, ideal, with no loss and no reactance.

Question 11

What happens to transmission lines at high frequencies?

Answer 11

They become complex with RLCG in the circuit.

Question 12

What is conductor heating loss also known as?

Answer 12

I2R loss and power loss

Question 13

Observable for solid dielectric lines but negligible for air dielectric; increases with frequency.

Answer 13

dielectric heating

Question 14

Occurs when a transmission line acts as an antenna; increases with frequency.

Answer 14

radiation loss

Question 15

Occurs whenever a connection is made to or from a transmission line or when two separate pieces are connected.

Answer 15

coupling loss

Question 16

What are the types of coupling loss?

Answer 16

• Lateral misalignment
• Gap displacement
• Angular misalignment

Question 17

A luminous discharge that occurs between two conductors when the potential difference exceeds the breakdown voltage.

Answer 17

corona or spark

Question 18

What do the telegrapher’s equations describe?

Answer 18

The voltage and current on an electrical transmission line with distance and time.

Question 19

What are primary line constants?

Answer 19

• Resistance
• Inductance
• Capacitance
• Conductance

Question 20

What are secondary line constants?

Answer 20

• Characteristic Impedance
• Propagation Constant
• Attenuation Constant
• Phase Constant

Question 21

What is the formula for inductance (L) for parallel wire lines?

Answer 21

L = (μ * s) / (ln(π * r))

Question 22

Measure of the superiority of a material over a vacuum as a path for magnetic lines of force.

Answer 22

permeability?

Question 23

What is the formula for capacitance (C) for parallel wire lines?

Answer 23

C = (π * ε) / (ln(s/r))

Question 24

What is the formula for resistance (R) for parallel wire lines?

Answer 24

R = 1 / (π * r * δ * σc)

Question 25

The velocity reduction ratio of electromagnetic waves that depends on the medium.

Answer 25

velocity factor (Vf)

Question 26

The ability to concentrate magnetic lines of force; pertains to the dielectric constant.

Answer 26

dielectric constant (k)

Question 27

Fill in the blank: The smaller the diameter of the wire, the _______ is the resistance.

Answer 27

[increases]

Question 28

Fill in the blank: The longer the transmission line, the _______ is the resistance.

Answer 28

[increases]