CWNA RF Fundamentals & Signal Propagation 2 — Questions and Answers
Question 1: Which type of antenna radiates power equally in all horizontal directions?
- Directional antenna
- Yagi antenna
- Omnidirectional antenna (Correct answer)
- Parabolic dish
Correct answer: Omnidirectional antenna
An omnidirectional antenna radiates power equally in all horizontal directions, creating a 360° coverage pattern.
Question 2: What does EIRP stand for in wireless networking?
- Effective Isotropic Radiated Power (Correct answer)
- Extended Internal Radio Protocol
- Effective Internal RF Power
- Enhanced Isotropic Relay Point
Correct answer: Effective Isotropic Radiated Power
EIRP (Effective Isotropic Radiated Power) represents the total power radiated by a transmitter compared to an isotropic antenna.
Question 3: Which frequency band typically experiences greater signal absorption by water vapor and building materials?
- 900 MHz
- 2.4 GHz
- 5 GHz
- Both 2.4 GHz and 5 GHz experience more than 900 MHz (Correct answer)
Correct answer: Both 2.4 GHz and 5 GHz experience more than 900 MHz
Both 2.4 GHz and 5 GHz suffer greater attenuation from obstacles than 900 MHz because shorter wavelengths are absorbed more readily by materials.
Question 4: What is the term for the loss of signal strength as it travels through free space without any obstacles?
- Insertion loss
- Return loss
- Free-space path loss (Correct answer)
- Noise floor degradation
Correct answer: Free-space path loss
Free-space path loss describes the reduction in signal power solely due to distance in an obstacle-free environment.
Question 5: In dB math, what does adding 3 dB to a power level represent?
- Triple the power
- Double the power (Correct answer)
- Half the power
- 10 times the power
Correct answer: Double the power
Adding 3 dB to a power level approximately doubles the power, since 10^(3/10) ≈ 2.
Question 6: Which type of fading is caused by the movement of people or objects in the environment during a wireless transmission?
- Fast fading
- Slow fading
- Rayleigh fading
- Both fast fading and Rayleigh fading (Correct answer)
Correct answer: Both fast fading and Rayleigh fading
Fast fading (also characterized as Rayleigh fading) results from rapid multipath changes caused by movement of objects or the transmitter/receiver.
CWNA RF Fundamentals & Signal Propagation 2
Which type of antenna radiates power equally in all horizontal directions?