Deck 2: Electrical Conductors and Cable

Question 1

Silver is the most commonly used conductor plating.

Answer 1

False

Question 2

Unwanted transfer of signals from one conductor to another is called crosstalk.

Answer 2

True

Question 3

Voltage loss is the result of _________.

A) Size, length and resistance of the wire
B) Old cable
C) Crosstalk
D) Poor shielding

Answer 3

A

Question 4

The conductivity of copper is rated at 100%.

Question 5

Foil shielding offers lower DC resistance and increases the strength of the cable.

Question 6

Braided shielding can achieve 100% cable coverage.

Question 9

The value of characteristic impedance for a line is determined by the ________.

A) Geometry of the conductors
B) Type of insulating material
C) Spacing
D) All the above

Question 10

The larger the wire gauge number the smaller the wire diameter.

Question 11

The characteristic impedance of a cable _________.

A) Changes with the length of the cable
B) Is a low frequency characteristic
C) Is always constant
D) Is not affected by the insulation of the conductors

Question 12

Cable capacitance combined with source and cable resistance form a __________.

A) High-pass filter
B) Low-pass filter
C) Band-pass filter
D) All the above

Question 13

The space above a suspended ceiling where ductwork is run is known as the plenum.

Question 14

Solid wire is preferred when wiring panels, controls, pumps, batteries and manufacturing test systems.

Question 16

What causes the conductive surface area of the cable to decrease as signal frequencies increase?

A) Characteristic Impedance
B) Changes in temperature
C) Skin effect
D) Bend radius

Question 17

Nickel plating is used for high temperature environments.

Question 18

Abandoned Class 2, Class 3, audio or communication cable are  ________.

A) Usually reclassified as Class 1 cables
B) Any cable not connected at one end and tagged for future use
C) Permitted to remain in a building or structure
D) Not a fire hazard

Question 19

The type of insulation does not affect the capacitance of the cable.

Question 21

Calculate the wavelength, in meters, of a 92MHz signal through a cable having a velocity factor of 80%.

Question 22

Calculate the voltage at a 15 Ω load, for a 20V source connected through 500ft. of cable, having a resistance of 6 Ω per 1000ft.

Question 25

Calculate the characteristic impedance of a 75 Ω coaxial cable running 600ft.

Question 26

A 0.025" conductor is equivalent to a circular mil size of _________.

Question 27

Calculate the velocity of propagation, in meters, for a cable having a velocity factor of 86%.

Question 30

Calculate the cutoff frequency for a signal through a resistance of 10K Ω and a capacitance of 500pF.