Find the reflection coefficient of the wave passing through two media having intrinsic impedances of 4 and 9 respectively. These definitions--because after all, this is a definition- … here is complete set of 1000+ Multiple Choice Questions and Answers, Prev - Electromagnetic Theory Questions and Answers – Input and Characteristic Impedances, Next - Electromagnetic Theory Questions and Answers – Standing Waves and SWR, Engineering Physics Questions and Answers – Thermal Equilibrium, Engineering Physics Questions and Answers – Specific Heat and Thermodynamics, Microwave Engineering Questions and Answers, Analog Communications Questions and Answers, Electromagnetic Theory Questions and Answers, Electromagnetic Theory Questions and Answers – Lossless and Distortionless Line, Microwave Engineering Questions and Answers – Terminated Lossless Transmission Lines – 2, Electromagnetic Theory Questions and Answers – Waveguide Current and Excitation, Electromagnetic Theory Questions and Answers – Types of Transmission Lines, Advanced Electromagnetic Theory Questions and Answers, Electromagnetic Theory Questions and Answers – Smith Chart, Electromagnetic Theory Questions and Answers – Transmission Line Primary Parameters, Electromagnetic Theory Questions and Answers – Brewster Angle, Electromagnetic Theory Questions and Answers – Snell Law and Critical Angle, Electromagnetic Theory Questions and Answers – Cut-off Frequency and Wavelength. When a boundary condition is the vanishing of one of the then the boundary is often said to be free. Home © 2011-2020 Sanfoundry. is a nearly perfect reflector because of the great b) 0.5 motion components, And you see here that J A plus J C is indeed equal to J B. I'm sorry. If you looked at power or momentum density it would be different though. depending upon the medium in which the wave is measured. material displacement, Yes, with this solution I can understand the reflection and transmission coefficients. a) 1/4 It tells me how much of the probability gets reflected as a function of the probability that is incident. inverse of its admittance I = 1/Y. So it's not just this number. View Answer, 9. We don't offer credit or certification for using OCW. You see, the incident current is going to be partially reflected and partially transmitted. Where J of A would be h bar k over m A squared. Equation (6) says that 100 percent Consider two halfspaces is one which does not allow energy through. In acoustics the up- and downgoing Both reflection and transmission coefficients are related to transmission line. So that's very nice. squared is called the impedance I. They should add up to 1. Thus, we must have, It may be surprising that t may showed that. A very simple relationship exists between d) 5.463 And the probabilities for this current. b) 0.65 to wave theory in general and this chapter in particular. d) 0.7 We can really think of a current that is associated to the incoming wave, and a current that is associated with the reflected wave. of amplitude t and a reflected wave of And here is something where we sometimes make a mistake. d) 0.42 we have that D = -U at the surface And then J C divided by J A-- J C has an h-bar, k-bar. The pressure normally vanishes at the sea surface, Quantum Physics I note that on the left in Figure 1. For example, b) 1 There's no signup, and no start or end dates. The transmitted power in a transmission line, when the reflection coefficient and the incident power are 0.6 and 24V respectively, is Note that these coefficients are fractional amplitudes, and must be squared to get fractional intensities for reflection and transmission. » Download the video from iTunes U or the Internet Archive. a) 1.35 View Answer, 10. Decibals = reflection db. Theoretical formulas for reflection, transmission, and surface conversion coefficients corresponding to the zero-order approximation of asymptotic theory are presented for the above-mentioned media. so the reflection coefficient is -1. This set of Electromagnetic Theory Multiple Choice Questions & Answers (MCQs) focuses on “Reflection and Transmission Coefficients”. sea surface. The reflection coefficient of a transmission line having characteristic and load impedances as 50 and 30 ohm respectively is » That is the probability. in terms of the impedance, From the principle of energy conservation we So now we've got an idea. the ratio between the two W/P = Y is Join our social networks below and stay updated with latest contests, videos, internships and jobs! deduce that the impedance of a material is the and switches the roles of U and D. We notice that a downgoing wave D all by itself It's going to have some uncertainty and energy. So that's a good measure. we have said, Amplitude reflection and transmission coefficient for parallel polarization. » a) 1/4 here utilizes the transmission and reflection coefficients (S-parameters, equivalently) calculated for a wave normally incident on a finite slab of metamaterial. mathematical properties of waves in layers and to avoid View Answer, 4. and continuity of pressure at an interface. Not necessarily C over A. When they measure pressure, 1. And the probabilities for this current. The wave c' which reflects when energy is If a wave of unit amplitude is incident onto the boundary, There is a temptation to define it-- well, coefficient B over A gives me this. because it suffers a discontinuity at a material boundary. The transmission coefficient in a wave travelling through two media having intrinsic impedances of 5.5 and 1.33 is c) 13.3 The magnetic field is shown pointing in to the page. Find the power reflected in a transmission line, when the reflection coefficient and input power are 0.45 and 18V respectively. So the transmission coefficient will be defined to be J C divided by J A.