Antennas Multiple Choice Questions on “Types of Polarization”.
1. Which of the following polarization is used in monopole antenna?
a) Right-hand Circular
b) Linear
c) Depends on the feed
d) Left-hand Circular
Answer: b
Clarification: The linear polarization takes place in the monopole dipole. In the Dipole also a linear polarization takes place. Parabolic reflectors take the polarization of the feed. In helical, circular loop antennas we can find the circular polarization.
2. Which type of polarization is found in parabolic reflector?
a) Right-hand Circular
b) Linear
c) Depends on the feed
d) Left-hand Circular
Answer: c
Clarification: The parabolic antennas take the polarization of the feed. The linear polarization takes place in the monopole dipole. In the Dipole also a linear polarization takes place. In helical, circular loop antennas we can find the circular polarization.
3. In which of the following polarization the electric field components are perpendicular to each other and have equal magnitude?
a) Linear
b) Vertical
c) Circular
d) Elliptical
Answer: c
Clarification: In linear components are in the same plane. Vertical and horizontal are types in linear polarization. Circular polarization has electric field components are perpendicular to each other and have equal magnitude. In elliptic, the electric field components are perpendicular to each other and have unequal magnitude.
4. In which of the following polarization the electric field components are perpendicular to each other and have unequal magnitudes?
a) Linear
b) Vertical
c) Circular
d) Elliptical
Answer: d
Clarification: In linear components are in the same plane. Vertical and horizontal are types in linear polarization. Circular polarization has electric field components are perpendicular to each other and have equal magnitude. In elliptic, the electric field components are perpendicular to each other and have unequal magnitude.
5. Tilt angle of the elliptic polarization with respect to horizontal is ____________
a) τ=(tan^{-1}(frac{a_{vertical}}{a_{horizontal}}))
b) τ=(frac{a_{horizontal}}{a_{vertical}})
c) τ=((frac{a_{vertical}}{a_{horizontal}}))
d) τ=(tan^{-1}(frac{a_{horizontal}}{a_{vertical}}))
Answer: a
Clarification: The two properties of ellipse that relates to the polarization are — eccentricity and tilt or inclination angle with respect to horizontal. Tilt angle of the elliptic polarization is given by
τ=(tan^{-1}(frac{a_{vertical}}{a_{horizontal}}))
6. The locus traced by the extremity of the time-varying field vector at a fixed observational point is called ________
a) polarization
b) gain
c) directivity
d) height
Answer: a
Clarification: The locus traced by the extremity of the time-varying field vector at a fixed observational point is called polarization. Gain is the output to input power ratio. Directivity is the amount of power radiated in the desired direction.
7. Which of the following is true for the circular polarization?
a) Ex=Ey, and ∅=π/2
b) Ex≠Ey, and ∅=π/2
c) Ex≠Ey, and ∅=π/4
d) Ex=Ey, and ∅=π/4
Answer: a
Clarification: The locus traced by the extremity of the time-varying field vector at a fixed observational point is called polarization. Circular polarization has electric field components are perpendicular to each other and have equal magnitude. Ex=Ey, and ∅=π/2.
8. Which of the following is true for the elliptical polarization?
a) Ex=Ey, and ∅=π/2
b) Ex≠Ey, and ∅=π/2
c) Ex≠Ey, and ∅=π/4
d) Ex=Ey, and ∅=π/4
Answer: b
Clarification: The locus traced by the extremity of the time-varying field vector at a fixed observational point is called polarization. In elliptical polarization, the electric field components are perpendicular to each other and have unequal magnitude.
Ex≠Ey,and ∅=π/2
9. The transmission mode polarization vector and receiving mode polarization vector of antenna polarization are ___________
a) always equal
b) conjugate to each other
c) negative of conjugate of other
d) inverse of Conjugate of other vector
Answer: b
Clarification: The antenna polarization is defined by the polarization vector it transmits. In a common coordinate system, the transmission mode polarization vector is the conjugate of its receiving mode polarization vector.
10. The linear and circular polarizations are special cases of elliptical polarization.
a) True
b) False
Answer: a
Clarification: In Elliptical polarization, if the amplitude is made equal, then it becomes a circular polarization. If the phase difference of the two linear components is zero or nπ then it is becomes a linear polarization. Therefore linear and circular polarization is a special case of elliptical polarization.