1. 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
Explanation: 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.
2. 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
Explanation: 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.
3. 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=\(tan^{-1}(\frac{a_{horizontal}}{a_{vertical}})\)
Explanation: 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=\(tan^{-1}(\frac{a_{vertical}}{a_{horizontal}})\)
4. 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
Explanation: 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.
5. 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
Explanation: 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.
6. 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
Explanation: 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
7. 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
Explanation: 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.
8. The linear and circular polarizations are special cases of elliptical polarization.
a) True
b) False
Explanation: 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.
9. What is the polarization loss factor due to mismatch if the two linear polarized antennas are rotated by an angle ∅?
a) tan∅
b) cos∅
c) cos2∅
d) cos-1∅
Explanation: The polarization loss factor describes the power loss due to polarization mismatch. The polarization loss factor due to mismatch if the two linear polarized antennas are rotated by an angle ∅ is given by PLF =cos2∅.
10. What is the polarization loss factor when a linear polarized antenna receives a circular polarized?
a) 0.5
b) 1
c) 0
d) 2
Explanation: Circular polarization is combination of two orthogonal linear polarized waves at 90° phase difference. The linear component just selects one in-phase component from this so ∅=45
⇨ PLF = cos2∅.=1/2=0.5