Which of the following expression is correct for radiation efficiency?(a) \(\eta_r=\frac{R_r}{R_l}\)(b) \(\eta_r=\frac{R_r}{R_r-R_l}\)(c) \(\eta_r=\frac{R_r}{R_r+R_l}\)(d) \(\eta_r=\frac{R_l}{R_r+R_l}\)I got this question during an interview.My doubt stems from Directive Gain in division Antenna Parameters of Antennas

Which of the following expression is correct for radiation efficiency?

1.	Which of the following expression is correct for radiation efficiency?(a) \(\eta_r=\frac{R_r}{R_l}\)(b) \(\eta_r=\frac{R_r}{R_r-R_l}\)(c) \(\eta_r=\frac{R_r}{R_r+R_l}\)(d) \(\eta_r=\frac{R_l}{R_r+R_l}\)I got this question during an interview.My doubt stems from Directive Gain in division Antenna Parameters of Antennas
Answer» Right option is (c) \(\eta_r=\frac{R_r}{R_r+R_l}\) Explanation: Radiation efficiency is DEFINED as the ratio of power radiated to the total input power to the antenna. Total input power is the sum of the radiated power PRAND the OHMIC losses Pl. \(\eta_r = \frac{P_r}{P_{in}} = \frac{P_r}{P_r+P_l} = \frac{R_r I_{rms}^2}{I_{rms}^2 R_r+I_{rms}^2 R_l} = \frac{R_r}{R_r+R_l} \)

Discussion

No Comment Found

Related InterviewSolutions

Let’s assume a transmitting antenna having gain 10dB is placed at a distance of 100m from the receiving antenna and radiates a power of 5W. Find the gain of the receiving antenna in dB when the received power is 150μW and transmitter frequency 500MHz?(a) 1.31dB(b) 1.19dB(c) 11.19dB(d) 13.16dBI had been asked this question in an online quiz.My doubt stems from Friis Transmission Equation topic in portion Antenna Parameters of Antennas
Power received by the antenna when one antenna is horizontally polarized and the other is vertically polarized is _______(a) 1(b) 0(c) \(\frac{P_r}{P_t} = \frac{G_t G_r λ^2}{(4πR)^2}\)(d) \(\frac{P_r}{P_t} = \frac{G_t G_r λ^2}{2(4πR)^2}\)This question was posed to me in an interview for internship.Enquiry is from Friis Transmission Equation topic in section Antenna Parameters of Antennas
Effective aperture is the ability of antenna to extract energy from the electromagnetic wave.(a) True(b) FalseI have been asked this question by my school principal while I was bunking the class.My question is taken from Effective Aperture topic in section Antenna Parameters of Antennas
The value of maximum power gain is always greater than or equal to the maximum directive gain.(a) True(b) FalseThis question was addressed to me during an interview.This intriguing question comes from Power Gain topic in portion Antenna Parameters of Antennas
For an isotropic source, Radiation intensity will be _____ on θ and ______ on Φ.(a) Dependent, independent(b) Independent, independent(c) Independent, dependent(d) Dependent, dependentI have been asked this question in homework.This key question is from Isotropic Radiators in chapter Antenna Parameters of Antennas
What is the maximum power gain when the radiation resistance is 72Ω, loss resistance is 8Ω and the maximum directive gain is 1.5?(a) 1.15(b) 1.35(c) 1.25(d) 1.53The question was posed to me in an internship interview.This interesting question is from Power Gain topic in portion Antenna Parameters of Antennas
Which of the following field varies inversely with r^2?(a) Far field(b) Near field(c) Radiation field(d) Electrostatic fieldThis question was addressed to me by my college professor while I was bunking the class.This interesting question is from Antenna Characteristics in division Antenna Parameters of Antennas
Quality factor is defined as ________(a) \(2π×\frac{energy \,radiated\, per\, cycle}{Total\, energy\, stored\, by\, antenna}\)(b) \(4π×\frac{Total \,energy \,stored \,by\, antenna}{energy\, radiated\, per \,cycle}\)(c) \(4π×\frac{energy \,radiated\, per \,cycle}{Total \,energy\, stored \,by \,antenna}\)(d) \(2π×\frac{Total \,energy\, stored\, by \,antenna}{energy\, radiated \,per \,cycle}\)The question was asked in final exam.This intriguing question comes from Antenna Bandwidth topic in portion Antenna Parameters of Antennas
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) 2.5ΩThe question was posed to me during an internship interview.The doubt is from Radiation Resistance in chapter Antenna Parameters of Antennas
The radiation efficiency value is ______(a) 0(b) 1

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment