Friis Transmission MCQs

Practice Friis Transmission MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1

Antenna & Wave PropagationFriis Transmission

The Friis free-space transmission equation is primarily used to estimate?

AReceived power between antennas in free-space far-field conditions
BConductor skin depth
CAntenna mechanical strength
DIonospheric critical frequency only

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Correct Answer: A. Received power between antennas in free-space far-field conditions

Explanation: The Friis equation relates transmitted power, antenna gains, wavelength and separation to received power under ideal free-space far-field conditions.

Reference: Standard antenna and wave propagation: friis transmission

Question 2

Antenna & Wave PropagationFriis Transmission

In ideal free-space propagation, if the distance between transmitting and receiving antennas is doubled while all other factors remain unchanged, received power becomes?

ATwice
BHalf
COne-fourth
DOne-eighth

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Correct Answer: C. One-fourth

Explanation: The Friis equation gives received power proportional to 1/R², so doubling distance reduces received power to one-fourth.

Reference: Standard antenna and wave propagation: friis transmission