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Right OPTION is (a) True

Explanation: In the EM WAVE propagation, the electric and magnetic FIELDS are perpendicular to each other. The P polarised wave is similar to the transverse electric (TE) wave, the magnetic field lies in the PLANE perpendicular to that of the interface or the electric field lies in the same plane as the interface.

Correct CHOICE is (d) 0.4

For explanation I would say: The TRANSMISSION coefficient is the REVERSE of the reflection coefficient. THUS T + τ = 1. On substituting for τ = 0.6, we get T = 0.4. It has no unit.

The correct option is (B) 1

Easiest explanation: The transmission coefficient is the ratio of the transmitted ELECTRIC field to the incident electric field. Thus T = Et/Ei. On SUBSTITUTING for Et = 5 and Ei = 5, we get T = 5/5 = 1(no unit). Simply, when the incident and transmitted field are same, no REFLECTION OCCURS and the transmission is unity.

Correct ANSWER is (b) 0.4

Easy EXPLANATION: The reflection COEFFICIENT is the ratio of the reflected electric FIELD to the incident electric field. Thus τ = Er/Ei. On substituting for Ei = 5 and Er = 2, we get τ = 2/5 = 0.4(no unit).

Correct option is (b) P polarised

To elaborate: The BREWSTER ANGLE is valid for perpendicular polarisation. The P polarised wave is ALSO a type of perpendicular polarisation. In P polarisation, the electric FIELD lies in the PLANE of the interface.

Correct ANSWER is (a) True

To explain: In the EM wave propagation, the electric and magnetic fields are perpendicular to each other. The S POLARISED wave is SIMILAR to the transverse magnetic (TM) wave, the electric FIELD lies in the plane perpendicular to that of the interface.

The correct OPTION is (d) 5

For EXPLANATION: The resultant electric field of two electric COMPONENTS Ex and Ey is E = √(Ex^2 + Ey^2). On substituting for Ex = 3 and Ey = 4, we GET E = 5 units.

The CORRECT OPTION is (a) Linear

To explain: The magnitude of the EX and Ey COMPONENTS are not the same. Thus it cannot be circular polarisation. For a phase difference of 0, the polarisation is linear. In other words, the waves are in phase. Thus the polarisation is linear.

Correct OPTION is (c) CIRCULARLY polarised

The explanation is: The polarisation of the transmitting and receiving antenna has to be the same. This is the condition for maximum POWER transfer to occur. This is POSSIBLE only when the polarisation is CIRCULAR.

The correct option is (d) Linear

For explanation: The magnitude of the Ex and Ey COMPONENTS are not the same. THUS it cannot be CIRCULAR polarisation. For a phase DIFFERENCE of 0, the polarisation is linear. In other words, the waves are in phase. Thus the polarisation is linear.

Right option is (a) True

The best I can EXPLAIN: The SNELL LAW is calculated from the oblique incidence media. Thus it is APPLICABLE for perpendicular polarisation. The BREWSTER law is applicable for perpendicular polarisation.

The correct option is (B) Right hand circularly polarised

To elaborate: The magnitude of the Ex and Ey components are the same. THUS it is circular POLARISATION. For -90 PHASE difference, the polarisation is right HANDED. In other words, the rotation is in anti-clockwise direction. Thus the polarisation is right hand circular.

Right choice is (a) Parallel

Explanation: When the EX is non-ZERO and the Ey is zero, the POLARISATION is parallel. The parallel polarisation is classified under the LINEAR polarisation TYPE.

The correct OPTION is (a) Left hand circularly polarised

To EXPLAIN: The magnitude of the Ex and Ey COMPONENTS are the same. Thus it is circular polarisation. For +90 phase difference, the polarisation is left HANDED. In other words, the rotation is in clockwise direction. Thus the polarisation is left hand circular.

Correct choice is (c) Left HAND elliptically polarised

Easiest EXPLANATION: The magnitude of the Ex and Ey components are not same. Thus it is elliptical polarisation. For +90 phase DIFFERENCE, the polarisation is left handed. In other words, the rotation is in CLOCKWISE direction. Thus the polarisation is left hand elliptical.

The correct answer is (b) ELLIPTICAL

Explanation: In elliptical polarisation, the MAGNITUDE of Ex and Ey COMPONENTS are not same. This is due to the VARIATION in the major and minor axes of the waves representing its magnitude.

Right ANSWER is (c) Linear

To explain I would say: The PHASE ANGLE between the Ex and Ey component is 0^0 and 180^0 for LINEARLY polarised wave. The wave is ASSUMED to be propagating in the z direction.

The correct answer is (a) 41.68

For EXPLANATION: The Snell law is GIVEN by N1 sin θi = N2 sin θt. To get θi, put N1 = 2, N2 = 1.3, θt = 45 DEGREE. THUS we get θi = sin^-1(1.3 sin 45)/2 = 41.68 degree.

Right ANSWER is (a) True

Easiest EXPLANATION: For COMPLETE wave reflection, the angle of INCIDENCE should be same as the angle of the reflection. In such cases, the reflection coefficient is unity and the TRANSMISSION coefficient is zero.

Correct ANSWER is (a) True

Easiest explanation: The critical angle is the minimum angle of INCIDENCE which is REQUIRED for the total internal reflection to occur. This is the angle that relates the refractive INDEX with the angle of reflection in an oblique incidence medium.

The CORRECT choice is (b) 2.45

To explain: The refractive index is GIVEN by n = c √(με), where c is the speed of light. Given that RELATIVE permittivity and relative PERMEABILITY are 2 and 3 respectively. THUS n = 3 x 10^8 √(2 x 4π x 10^-7 x 3 x 8.854 x 10^-12) = 2.45.

Right choice is (a) 0.71

For EXPLANATION: The Snell law is given by N1 sin θi = N2 sin θt. To get sin θi/sin θt, the ratio is N2/N1. On substituting for N1 = 2.33 and N2 = 1.66, we get 1.66/2.33 = 0.71.

The CORRECT choice is (a) N1 SIN θi = N2 sin θt

For explanation: The SNELL law states that in an oblique medium, the product of the refractive index and SINE of incidence angle in medium 1 is same as that of medium 2. THUS it is given by N1 sin θi = N2 sin θt.

Right option is (d) 1.732

For explanation I would say: The tangent of the Brewster angle is the ratio of the MEDIUM 2 permittivity to the medium 1 permittivity. Thus tan θb = (n2/n1). Given that θb = 60 DEGREE, the ratio n2/n1 will be tan 60 = 1.732.

The CORRECT option is (B) False

Easiest explanation: Any polarised wave transmitted at the Brewster angle will be linearly polarised. It can be a parallel, PERPENDICULAR, circular or elliptical POLARISATION. The resultant wave is always linearly polarised. This is the reason why the Brewster angle is called polarisation angle.

The correct CHOICE is (a) True

Easy explanation: The Brewster angle is SAID to be the polarisation angle. When a CIRCULARLY polarised wave is incident at the Brewster angle, the RESULTANT wave will be linearly polarised.

Right answer is (b) 1

The explanation is: The TRANSMISSION COEFFICIENT is the REVERSE of the reflection coefficient. At Brewster angle, the reflection will be zero. Thus the transmission is T = 1-R. Since R = 0, T = 1. It is to be noted that T and R lies in the range of 0 to 1.

The correct choice is (C) 4

The BEST explanation: The refractive index is the square root of the permittivity. Thus N = √ε. Given that ε = 16, we get refractive index as n = 4. It has no UNIT.

The correct CHOICE is (a) 0

To elaborate: Brewster angle propagation refers to complete transmission. The wave TRANSMITTED at the Brewster angle will be COMPLETELY transmitted without reflection. THUS the reflection COEFFICIENT will be zero.

Right CHOICE is (b) Parallel

To explain I would say: The parallel POLARISATION of the electromagnetic waves is possible only when the transmission occurs at the Brewster ANGLE.

Right answer is (b) 1.9

For EXPLANATION I would say: The numerical aperture is given by NA = N cos θc, where θc is the critical ANGLE and n is the REFRACTIVE INDEX. On substituting for n = 2.33 and θc = 35, we get NA = 2.33 cos 35 = 1.9(no unit).

The correct ANSWER is (b) False

For explanation: The LIGHT should pass through the core region only, for EFFECTIVE transmission. When light passes through CLADDING, losses will occur, as cladding is meant for protection. Thus core refractive index must be greater than the cladding refractive index.

The correct answer is (a) 1.15

The explanation is: The numerical aperture is given by NA = n sin θa, where n is the refractive INDEX. It is 1.33 for WATER medium. Given that the acceptance ANGLE is 60, we GET NA = 1.33 sin 60 = 1.15.

The correct option is (c) 45

Easy explanation: The numerical APERTURE is GIVEN by NA = n SIN θa, where n is the refractive index. It is unity in air. Thus NA = sin θa. To GET θ= sin^-1(NA), put NA = 0.707, thus θa = sin^-1(0.707) = 45 degree.

Correct option is (d) 1.86

For explanation: The NUMERICAL aperture is given by NA = √(N1^2 – n2^2), where n1 and n2 are the refractive indices of CORE and cladding RESPECTIVELY. On substituting for n1 = 2.33 and n2 = 1.4, we get NA = √(2.33^2-1.4^2) = 1.86.

The CORRECT OPTION is (a) True

Easy explanation: The VELOCITY of light in the air medium and the speed of light are both the same. SINCE light travels at maximum velocity in air only. Thus the refractive index N = c/v will be unity.

Correct option is (d) 2

Easiest EXPLANATION: The refractive INDEX is given by the ratio of the speed of light to the VELOCITY in a PARTICULAR medium. It is given by n = c/v. On substituting for v = 1.5 x 10^8 and c = 3 x 10^8, we get n = 3/1.5 = 2. The quantity has no unit.