This set of Antenna Multiple Choice Questions & Answers (MCQs) focuses on “Radiation Resistance”.

1. What is the radiation resistance of an antenna if input power to it is 1KW and current in it is 10A having a power loss of 200W?
a) 10Ω
b) 2Ω
c) 12Ω
d) 8Ω

2. What is the radiation resistance of a short dipole of length L?
a) 20π2 (\frac{L}{\lambda})^2
b) 80π2 (\frac{l}{\lambda})^2
c) 40π2 (\frac{l}{\lambda})^2
d) 160π2 (\frac{l}{\lambda})^2

3. What is the radiation resistance of an antenna if it radiates 1kW and current in it is Irms=10A?
a) 0.1Ω
b) 1Ω
c) 10Ω
d) 100Ω

4. If the length of the dipole decreases, then the radiation resistance will________
a) increase
b) decrease
c) depends on current distribution
d) not change

5. Find the radiation resistance of a Hertzian dipole of length 1m and operating at a frequency 1MHz?
a) 0.08Ω
b) 8.8mΩ
c) 8.8Ω
d) 0.88Ω

6. What is the radiation resistance of the antenna radiating at 5kW and having maximum current 2A?
a) 25kΩ
b) 2.5kΩ
c) 0.25kΩ
d) 2.5Ω

7. For a half-wave dipole with length λ/12, what is the antenna efficiency if the Radiation resistance is 2Ω?
a) 0.73
b) 0.073
c) 0.37
d) 0.78

8. Radiation resistance doesn’t depend on direction of power radiated but depends on the frequency.
a) True
b) False

9. Power radiated by half-wave dipole with maximum current amplitude 10A is ______
a) 3.65kΩ
b) 3.650Ω
c) 0.365kΩ
d) 36.50Ω

10. The radiation resistance dissipates same amount of power as it radiated by the antenna.
a) True
b) False 5 Star
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