An 8-isotropic element broadside array separated by a λ/4 distance has nulls occurring at ____(a) cos^-1(±n)(b) \(cos^{-1} (±\frac{n}{2})\)(c) \(sin^{-1} (±\frac{n}{2})\)(d) \(sin^{-1} (±n)\)The question was asked in an interview for job.This is a very interesting question from Radiation Pattern of 8-Isotropic Elements topic in portion Antenna Array of Antennas

An 8-isotropic element broadside array separated by a λ/4 distance ha

1.	An 8-isotropic element broadside array separated by a λ/4 distance has nulls occurring at ____(a) cos^-1(±n)(b) \(cos^{-1} (±\frac{n}{2})\)(c) \(sin^{-1} (±\frac{n}{2})\)(d) \(sin^{-1} (±n)\)The question was asked in an interview for job.This is a very interesting question from Radiation Pattern of 8-Isotropic Elements topic in portion Antenna Array of Antennas
Answer» Correct answer is (b) \(cos^{-1} (±\frac{n}{2})\) Best explanation: The nulls of the N- element array is GIVEN by \(θ_n=cos^{-1}⁡(\frac{λ}{2πd}\LEFT[-β±\frac{2πn}{N}\RIGHT])=cos^{-1}⁡(\frac{λ}{2πd} [±\frac{2πn}{N}])\) ⇨ \(θ_n=cos^{-1}⁡(\frac{λ}{2π(λ/4)}) [±\frac{2πn}{N}])=cos^{-1} (±\frac{4n}{8})=cos^{-1} (±\frac{n}{2})[n=1,2,3 \,and\, n≠N,2N…]\)

Discussion

No Comment Found

Related InterviewSolutions

The Half-power beam width of the N-element isotropic source array can be known when _____(a) \(ᴪ=\frac{2.782}{N}\)(b) \(ᴪ=\frac{1.391}{N}\)(c) \(ᴪ=\frac{1.414}{N}\)(d) \(ᴪ=\frac{3}{N}\)I had been asked this question in quiz.My doubt stems from Array of N-Isotropic Sources in section Antenna Array of Antennas
The necessary condition for maximum of the first side lobe of n element array is ______(a) \(\frac{Nᴪ}{2}=±\frac{5π}{2}\)(b) \(\frac{Nᴪ}{2}=±\frac{3π}{2}\)(c) \(\frac{Nᴪ}{2}=±\frac{π}{2}\)(d) \(\frac{Nᴪ}{2}=±\frac{4π}{2}\)I had been asked this question in class test.The above asked question is from Radiation Pattern of 8-Isotropic Elements topic in portion Antenna Array of Antennas
Which of the following statements is false regarding a broadside array?(a) The maximum radiation is normal to the axis of the array(b) Must have same amplitude excitation but different phase excitation among different elements(c) The spacing between elements must not equal to the integral multiples of λ(d) The phase excitation difference must be equal to zeroThis question was posed to me in unit test.The above asked question is from Broadside Array topic in portion Antenna Array of Antennas
Which of the following is true for uniform linear array elements, to obtain the total field?(a) The single element field is multiplied by the array factor(b) The single element field is multiplied by the normalized array factor(c) The single element field is multiplied by the beamwidth(d) The single element field is multiplied by the directivityI got this question during an interview.I'm obligated to ask this question of Factors topic in division Antenna Array of Antennas
Normalized array factor of N –element linear array is ________(a) \(\frac{sin(Nᴪ/2)}{Nᴪ/2} \)(b) \(\frac{cos(Nᴪ/2)}{Nᴪ/2} \)(c) \(N\frac{sin(ᴪ/2)}{ᴪ/2} \)(d) \(N\frac{cos(Nᴪ/2)}{Nᴪ/2} \)The question was asked in homework.Question is from N-element Linear Array topic in portion Antenna Array of Antennas
Which of the following is false regarding Antenna array?(a) Directivity increases(b) Directivity decreases(c) Beam width decreases(d) Gain increasesI had been asked this question in an online interview.The doubt is from Introduction topic in division Antenna Array of Antennas
Find the angle at which nulls occur for the two element array antenna with separation λ/4 and phase difference is -π/2?(a) 0(b) π/2(c) π/4(d) πThis question was addressed to me during an interview.The origin of the question is Factors topic in chapter Antenna Array of Antennas
The radiating pattern of single element multiplied by the array factor simply gives the ___________(a) Pattern multiplication(b) Normalized array factor(c) Beamwidth of the array(d) Field strength of the arrayThe question was asked in a national level competition.The doubt is from N-element Linear Array in chapter Antenna Array of Antennas
Total resultant field obtained by the antenna array is given by which of following?(a) Vector superposition of individual field from the element(b) Maximum field from individual sources in the array(c) Minimum field from individual sources in the array(d) Field from the individual sourceI had been asked this question in a job interview.This interesting question is from Introduction in section Antenna Array of Antennas
For long distance communication, which of the property is mainly necessary for the antenna?(a) High directivity(b) Low directivity(c) Low gain(d) Broad beam widthThis question was addressed to me in semester exam.This question is from Introduction in portion Antenna Array of Antennas

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment