Zero Reflection For P-Polarised Wave and Brewster Angle MCQ Quiz in தமிழ் - Objective Question with Answer for Zero Reflection For P-Polarised Wave and Brewster Angle - இலவச PDF ஐப் பதிவிறக்கவும்
Last updated on Mar 22, 2025
Latest Zero Reflection For P-Polarised Wave and Brewster Angle MCQ Objective Questions
Top Zero Reflection For P-Polarised Wave and Brewster Angle MCQ Objective Questions
Zero Reflection For P-Polarised Wave and Brewster Angle Question 1:
A uniform plane wave travelling from a medium with (ϵr = 2) is incident on a medium obliquely as shown in below figure,
E = (3âx – 4âz) cos [2π × 107t – 7(3z + 4x)] V/m
If the entire incident power is absorbed by the medium (2) then the relative permittivity of medium (2) is _______.
Answer (Detailed Solution Below) 3.3 - 3.7
Zero Reflection For P-Polarised Wave and Brewster Angle Question 1 Detailed Solution
Entire incident power is absorbed, hence there is no reflected wave.
⇒ Incident angle is Brewster’s angle.
From the given E-field we can deduce that wave is traveling x-z plane with vector along wave transfer is 4âx + 3âz.
The angle it makes with normal to plane of incident i.e. âz is
\(\Rightarrow \tan {\theta _i} = \frac{4}{3}\)
Brewster angle be, \({\theta _i} \Rightarrow \tan {\theta _B} = \sqrt {\frac{{{\varepsilon _2}}}{{{\varepsilon _1}}}} \)
\(\frac{4}{3} = \sqrt {\frac{\varepsilon }{2}} \)
\(\begin{array}{l} \frac{{16}}{9} = \frac{\varepsilon }{2}\\ \varepsilon = \frac{{32}}{9} \end{array}\)
≃ 3.55
Zero Reflection For P-Polarised Wave and Brewster Angle Question 2:
A plane wave is obliquely incident on a lossless dielectric (with its E-field parallel to plane of incidence) of an angle θ such that entire wave energy is transmitted, θ is ________ (in degrees) given ϵr = 2.5
Answer (Detailed Solution Below) 57.6 - 57.8
Zero Reflection For P-Polarised Wave and Brewster Angle Question 2 Detailed Solution
The angle of incidence of plane wave on a dielectric material such that entire wave is transmitted is called Brewster angle θb
\(\begin{array}{l} \sin {\theta _b} = \frac{1}{{\sqrt {1 + \frac{{{\epsilon_1}}}{{{\epsilon_2}}}} }}\\ = \frac{1}{{\sqrt {1 + \frac{1}{{{\epsilon_r}}}} }}\\ = \frac{1}{{\sqrt {1 + 0.4} }}\\ = \frac{1}{{\sqrt {1.4} }}\\ \Rightarrow {\theta _b} = {\sin ^{ - 1}}\left( {\frac{1}{{\sqrt {1.4} }}} \right) \end{array}\)
≃ 57.7
Zero Reflection For P-Polarised Wave and Brewster Angle Question 3:
A right circularly polarized (RCP) plane wave in a dielectric of relative permittivity \(\rm{\varepsilon_r = 3}\) is incident at an angle \(\rm{30^\circ}\) to the normal on a dielectric air interface. The polarization of the reflected and the transmitted wave respectively is –
Answer (Detailed Solution Below)
Linear, Elliptical
Zero Reflection For P-Polarised Wave and Brewster Angle Question 3 Detailed Solution
The RCP wave can be represented as the vector sum of s–polarized and p-polarized component. Now, we see for our case of incident angle 30°,
\(\tan 30^\circ = \frac{1}{{\sqrt 3 }} = \sqrt {\frac{{{ \in _{{r_2}}}}}{{{ \in _{{r_1}}}}}} = \sqrt {\frac{1}{3}}\)
Thus, \(\rm{\theta_i = 30^\circ}\) is the Brewster angle.
⇒ p-polarized wave will have zero reflection and complete transmission.
⇒ reflected wave will have only one component
⇒ reflected wave will be linearly polarized
Now, for s–polarized and p-polarized waves
Reflection coefficient, \({\Gamma _s} \ne {\Gamma _p}\) (except for normal incidence)
\(\eqalign{ & 1 + {\Gamma _s} \ne 1 + {\Gamma _p} \cr & \Rightarrow {\tau _s} \ne {\tau _p} \cr}\)
⇒ Transmission coefficients are not equal.
⇒ The transmitted s-polarized and p-polarized electric field phasor will have different amplitudes upon transmission and will be out of phase by \(90^\circ\).
⇒ Transmitted wave is elliptically polarized.