Deck 3: Radio Frequency Fundamentals

Question 1

Which value can be measured by the circuitry on a wireless NIC to determine if it is clear to send its transmission?

A) dB
B) RSSI
C) mW
D) SNR

Answer 1

B

Question 2

Which is caused by small objects or rough surfaces as an RF signal travels through the air?

A) reflection
B) refraction
C) scattering
D) nullification

Answer 2

C

Question 3

The ASK 1 bit has a carrier signal (positive voltage)while a 0 bit has no signal (zero voltage).

Answer 3

True

Question 4

When an RF signal moves from one medium to another of a different density the signal actually bends instead of traveling in a straight line.This is known as ____.

A) reflection
B) absorption
C) refraction
D) scattering

Question 5

The term ____ describes the rate of electrical flow.

A) voltage
B) current
C) resistance
D) electrical power

Question 6

What is the positive difference in amplitude between two signals?

A) propagation
B) gain
C) refraction
D) delay spread

Question 7

One of the units of measurement used to represent RF signal strength is Ohms.

Question 8

Electromagnetic waves travel through space at the speed of light.

Question 9

What units are used to measure RF power gain and loss on a relative scale?

A) dB
B) V
C) mW
D) ohm

Question 10

Whenever a wave moves to the maximum voltage,then down to the minimum voltage,and then returns back to the starting point,it has finished two cycles.

Question 11

Which is a method of measuring RF power that can be used as a comparison between two values and gives a better picture of the loss or gain?

A) continuous scale
B) linear scale
C) absolute scale
D) relative scale

Question 12

Which of the following units is used to measure frequency?

A) decibel
B) volt
C) hertz
D) byte

Question 13

____ modulation changes the number of waves representing one cycle.

A) Amplitude
B) Phase shift
C) Frequency
D) Phase

Question 14

Which describes the natural loss of signal strength through space?

A) scattering
B) absorption
C) free space loss
D) delay spread

Question 15

What is the term that describes the ratio of desired signal to undesired signal in the average power level of a transmission?

A) SNR
B) dBm
C) RSSI
D) FSPL

Question 16

Power of an electromagnetic signal such as one used in WLANs is measured by which unit?

A) millivolts
B) milliamps
C) milliohms
D) milliwatts

Question 17

Which binary modulation technique is similar to frequency modulation?

A) amplitude shift keying
B) frequency shift keying
C) phase shift keying
D) All of the above

Question 18

Which of the following is an electromagnetic wave?

A) light
B) heat
C) radio
D) All of the above

Question 19

Mulitple copies of an RF signal may reach the receiver at different times due to reflection.

Question 20

Which type of modulation changes the starting point of the cycle to represent a change from a 1 bit to a 0 bit and vice versa?

A) AM
B) FM
C) DM
D) PM

Question 21

What is the receive signal strength indicator?

Question 22

Which of the following are characteristics of electromagnetic waves (Choose all that apply.)

A)square
B)continuous
C)discrete
D)cycle

Question 23

What does a loss of 10 decibels mean with respect to the percent of power loss in mW?

A) 50%
B) 10%
C) 30%
D) 90%

Question 24

Resistance is measured in ohms and the total amount of resistance is called the ____________________.

Question 25

What are the negative effects of delay spread? (Choose all that apply.)

A)upfade
B)amplification
C)corruption
D)nulling

Question 26

Which of the following are used to describe the behaviors of waves as they propagate? (Choose all that apply.)

A)diffraction
B)scattering
C)resistance
D)absorption

Question 27

____________________ shift keying is a binary modulation similar to phase modulation.

Question 28

How is RF power measured using a relative scale?

Question 29

Describe electromagnetic waves.

Question 30

RF power gain and loss on a relative scale are measured in ____________________ instead of mW.

Question 31

There are several advantages of digital modulation over analog modulation.What are they?

Question 32

What is the difference between an analog and digital signal? Provide an example of each signal type.

Question 33

List three of the five behaviors that an electromagnetic wave may take as it propagates.

Question 34

What is amplitude modulation?

Question 35

Define the signal-to-noise ratio.

Question 36

What phenomenon is described as multiple copies of a signal that reach a receiver at different times?

A) propagation
B) multipath
C) multimode
D) multi-directional

Question 37

Which of the following are advantages of digital modulation over analog moduation? (Choose all that apply.)

A)makes better use of the available spectrum
B)performs better when interference is present
C)more power is required to transmit
D)frequency and phase changes occur continuously

Question 38

A(n)____________________ signal has numerous starts and stops throughout the signal stream.

Question 39

The way in which RG signals travel is referred to as wave ____________.

Question 40

What is the propagation behavior known as multipath?

Question 41

List the four properties that are used to describe an electromagnetic wave.