Antennas Mock Test 2

10%

Question 1 of 10

1. What is a Balun?

A twisted wire

It unbalances the balanced systems

Main beam of antenna with large beam width

It is used to balance the unbalanced systems

Question 1 of 10

Question 2 of 10

2. Find the effective noise temperature if noise figure is 3 at room temperature (290K)?

290K

580K

289K

195K

Question 2 of 10

Question 3 of 10

3. Which of the following Maxwell equation is correct for a non-conducting and lossless medium?

∇×E=0

∇×D=ρ_v

∇.D=0

∇.D=ρ_v

Question 3 of 10

Question 4 of 10

4. Gauss for the Magnetic Field is given by ______

∇.B=ρ_v

∇×B=0

∇.B=0

∇×B=ρ_v

Question 4 of 10

Question 5 of 10

5. What is the distance between antennas to apply the Friss transmission equation in terms of antennas largest dimension?

R » 2D²/λ

R « 2λ²/D

R « 2D²/λ

R » 2λ²/D

Question 5 of 10

Question 6 of 10

6. In which of the following the power is radiated through a complete spherical surface?

Neither Half-wave dipole nor Quarter-wave Monopole

Both Half-wave dipole & Quarter-wave Monopole

Quarter-wave Monopole

Half-wave dipole

Question 6 of 10

Question 7 of 10

7. What is the Beam area in radians when the HPBW in perpendicular planes are given by 60°, 30°?

\(\frac{\pi^2}{8}\)

\(\frac{\pi^2}{18}\)

\(\frac{\pi}{2}\)

Question 7 of 10

Question 8 of 10

8. Relation between beam efficiency and stray factor is given by ____

∈_B+∈_s=1

∈_B-∈_s=1

∈_B+∈_s=2

\(\frac{\in_B}{\in_s}=1\)

Question 8 of 10

Question 9 of 10

9. Power radiated by a Hertzian dipole of length λ/30 and carrying a current 2A?

8.77W

0.87W

2.51W

3.51W

Question 9 of 10

Question 10 of 10

10. Free space loss factor is given by _____

\(\frac{4\pi R}{\lambda}\)

\(\frac{\lambda}{4\pi R}\)

\((\frac{\lambda}{4\pi R})^2\)

\((\frac{4\pi R}{\lambda})^2\)

Question 10 of 10