Parabolic Reflector MCQs

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

Question 1

Antenna & Wave PropagationParabolic Reflector

A parabolic reflector antenna produces high directivity mainly because it?

AForms a large effective aperture and converts spherical wavefronts to approximately planar wavefronts
BRadiates equally in all directions
CUses only a resistive load
DHas zero physical aperture

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Correct Answer: A. Forms a large effective aperture and converts spherical wavefronts to approximately planar wavefronts

Explanation: With a feed near its focus, a paraboloid collimates radiation into a narrow beam, giving high gain/directivity.

Reference: Standard antenna and wave propagation: parabolic reflector

Question 2

Antenna & Wave PropagationParabolic Reflector

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Correct Answer: A. Increases gain and narrows the beam

Explanation: Reflector gain is approximately proportional to (D/lambda)², so a larger diameter gives higher gain and a narrower beam.

Reference: Standard antenna and wave propagation: parabolic reflector

Question 3

Antenna & Wave PropagationParabolic Reflector

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Correct Answer: A. (D/lambda)² times aperture efficiency

Explanation: A common reflector relation is G≈eta_a(pi D/lambda)², so gain scales with (D/lambda)² for fixed efficiency.

Reference: Standard antenna and wave propagation: parabolic reflector

Question 4

Antenna & Wave PropagationParabolic Reflector

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Correct Answer: C. 2369

Explanation: G≈0.6(pi×2/0.1)²=0.6(20pi)²≈2369, about 33.7 dBi.

Reference: Standard antenna and wave propagation: parabolic reflector