(1)Reflection coefficient (2) Standing wave ratio
Reflection coefficient R=Er/Ei
(2) Standing wave ratio
Description : For a transmission line, the incident voltage. Ei = 6V and Er =2V ,Calculate: (i) Reflection Coefficient (ii) SWR
Answer : Reflection Coefficient(K) = Er / Ei = 2V / 6V K = 0.333 SWR = 1+K / 1- K = 1+0.333 / 1-0.333 = 1.333 / 0.667 SWR= 1.998
Description : a) For a transmission line, Find SWR and reflection coefficient R if, i. There is no reflected voltage. ii. Reflected voltage and incident voltage is equal. iii. If reflected voltage=20V and incident voltage=10V. iv. If reflected voltage=10V and incident voltage =20V.
Answer : reflection coefficient R=Vr/Vi i. There is no reflected voltage. i.e,Vr=0 R=0 SWR= 1+R/1-R=1 ii. Reflected voltage and incident voltage is equal. Vr=Vi; R=1 SWR= 1+R/1-R=1+1/1-1=infinity iii. If reflected ... and incident voltage =20V. Vr=10 and Vi=20 R=10/20=0.5 SWR= 1+R/1-R=1+.5/1-.5=3
Description : If Voltage Standing Wave Ratio, (VSWR) of a wave is 2, its reflection coefficient will be _____.
Answer : If Voltage Standing Wave Ratio, (VSWR) of a wave is 2, its reflection coefficient will be 1/3.
Description : Calculate the characteristics impedance for a transmission line having L=0.5 mH/Km, C=0.08 µF and negligible R and G.
Answer : L=0.5 mH/Km C=0.08 µF
Description : Define standing wave ratio.
Answer : Standing wave ratio is defined as the ratio of maximum voltage (Vmax) to minimum voltage (Vmin). Standing wave ratio is also defined as the ratio of maximum current (Imax) to minimum current (Imin).
Description : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.
Answer : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.
Description : A load of 200 ohm is used to match 300 ohm transmission line to achieve SWR=1. Find out the required characteristic impedance of a quarter of a quarter wave transformer connected directly to the load.
Answer : Solution :
Answer : Whenever a wave is incident on a perfect conductor then the reflection coefficient is 0.
Description : The standing wave ratio of a 75 Ω transmission line used to feed a 300 Ω resistive load will be _____.
Answer : The standing wave ratio of a 75 Ω transmission line used to feed a 300 Ω resistive load will be 4.
Description : Draw waveform for standing waves on an open and shorted line. Prove that impedance is inverted at every quarter wavelength interval.
Answer : Waveform- Explanation When the transmission line is short circuited voltage is zero and current is maximum.The variation is according to the wavelength. When the ... The pattern repeats for every half wavelength. Thus impedance is inverted at every quarter wavelength interval.
Description : The reflection coefficient of a short-circuited line for voltage is: A) -1 B) +1 C) 0.5 D) zero
Answer : The reflection coefficient of a short-circuited line for voltage is: -1
Description : A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient? A) 0.69 B) 1.69 C) 6.9 D) 16.9
Answer : A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient? A) 0.69 B) 1.69 C) 6.9 D) 16.9
Description : A transmission line is terminated at its characteristic impedance. The reflection coefficient is (a) 1 (b) –1 (c) 0 (d) ∞
Answer : A transmission line is terminated at its characteristic impedance. The reflection coefficient is 0
Description : 220kV three phase transmission line is 60 km long. The resistance is 15 Ohms per phase and the inductance is j 30 Ohms. 1- Calculate : voltage regulation, TL line power losses and efficiency when ... for 0.85, calculate zise of the required capacitor and the same parameters which were in part 1
Description : State and explain the losses in transmission line.
Answer : Losses in Transmission Line:- There are three ways in which energy, applied to a transmission may desperate before reaching the load. They are 1) Radiation Losses:- Its occurs when a ... down voltage of the dielectric insulator. Generally when corona occurs, the transmission line is destroyed.
Description : Define the transmission line? Draw it‟s general equivalent circuit.
Answer : Transmission line: A conductor or conductors designed to carry electricity or an electrical signal over large distances with minimum losses and distortion. Equivalent circuit:
Description : Draw general equivalent circuit of transmission line.
Answer : Fig. General Equivalent circuit of transmission line
Answer : When a wave propagates on a transmission line, it suffers reflection several times at sending and other end.
Description : Ideally Voltage Standing Wave Ratio (VSWR) should be (a) as large as possible (b) as small as possible (c) as close to unity as possible (d) infinity
Description : Calculate characteristic impedance (Zo) for parallel and co-axial cables.
Answer : characteristic impedance for parallel cable characteristic impedance for co-axial cable Zo =Characteristic impedance D=Diameter of outer conductor d= Diameter of inner conductor E=Dielectric constant
Description : The coefficient of reflection for current wave is
Answer : The coefficient of reflection for current wave is 1 or -1
Description : A light wave is incident over a plane surface with velocity x. After reflection the velocity becomes :
Answer : x
Description : Explain standing waves with load terminal open circuited and short circuited.
Answer : Standing waves with load terminal open circuited Standing waves: The forward and reflected waves on the incorrectly terminated transmission line produce an interference pattern known as Standing ... , the load impedance will not be equal to the transmission line (characteristic)impedence.
Description : A wave and its reflection produce a standing wave with the distance from NODE to nearest ANTINODE of 4 meters. The wavelength of this wave is: w) 4 meters x) 8 meters y) 12 meters z) 16 meters
Answer : ANSWER: Z -- 16 METERS
Description : Define VSWR with refernce to standing waves.
Answer : Voltage Standing Wave Ratio: The voltage standing wave ratio (VSWR) is the ratio of max voltage to min voltage. VSWR= VMAX /VMIN
Description : For a battery with constant voltage, the reflection coefficient is (a) ∞ (b) – 1 (c) 1 (d) 0
Answer : 0
Description : In case of open circuited transmission lines the reflection coefficient is given by (A) 1 (B) -1 (C) 0.5 (D) 0
Description : Which physical phenomenon or principle is most often applied in the search for petroleum reservoirs? w) magnetic field distortions x) electromagnetic radiation y) natural radioactive decay of minerals z) acoustic wave transmission and reflection
Answer : ANSWER: Z -- ACOUSTIC WAVE TRANSMISSION AND REFLECTION
Description : Which physical phenomenon or principle is most often applied in the search for petroleum reservoirs? w) gravitational attraction x) magnetic field distortions y) natural radioactive decay of minerals z) acoustic wave transmission and reflection
Answer : ANSWER: Z -- ACOUSTIC WAVE TRANSMISSION AND REFLECTION
Description : How quarter wave transformer is used for impedance matching.
Answer : In all applications of transmission line, it is required that the load be matched to line, Which requires tuning out the unwanted load reactance and the transformation of resulting impedance to the required value ... Step down transformer If ZL <Zo then it acts as a Step up transformer
Description : Draw the radiation pattern for Dipole antenna: (i) Half wave dipole (ii) Folded dipole.
Answer : The radiation pattern for Half wave dipole antenna The radiation pattern for Folded dipole antenna.
Description : Explain the following in wave propagation: 1) Actual height 2) Virtual height
Answer : 1) Actual height:- The height attained by the wave during propagation through the ionosphere is known as Actual height. 2)Virtual height: -The incident wave returns back to the earth due to ... It is also defined as the maximum height that the hypothetical reflected wave would have reached.
Description : For a balanced three phase star connected load for which line voltage is 230V and per phase resistance and reactance is 6 Ohm and 8 Ohm respectively. Calculate: 1) phase voltage 2) line current 3) power factor 4) total power absorbed
Description : Show that AM wave consist of two side bands and carrier. Also prove the bandwidth of AM is double of the modulating frequency.
Description : Compare ground wave propagation. Sky wave propagation and space wave propagation.
Answer : Sr. N o Parameter Ground Wave Propagation Sky Wave Propagation Space wave Propagation 1 Frequency Range 30 kHz to 3 MHz 3 MHz to 30 MHz frequencies above 30 MHz 2 ... These waves have line of sight propagation, ... 6 Fading Problem less Severe Less
Description : Define electromagnetic wave and polarization.
Answer : Electromagnetic wave:-An electromagnetic wave such as light consists of a coupled oscillating electric field and magnetic field which are always perpendicular; by convention Polarization:-polarization" of electromagnetic waves refers to the direction of the electric field.
Description : Describe the term virtual height with the help of diagram showing ionized layer and the path of wave.
Answer : Virtual height: -The incident wave returns back to the earth due to refraction. In this process it bends down gradually and not sharply, but the incident and reflected rays follow exactly ... . It is also defined as the maximum height that the hypothetical reflected wave would have reached.
Description : Compare ground wave and space wave propagation on the basis of: (i) Frequency range (ii) Method of propagation.
Answer : Compare ground wave and space wave propagation on the basis of: (i) Frequency range (ii) Method of propagation.
Description : List and explain the properties of quarter wave transformer.
Answer : Properties of quarter wave transformer: 1. Impedance transfomation: it provides impedance transformation upto the highest frequencies and is compatible with transmission line. 2. Impedance inversion: if ZL is ... or step up transformer,depending on whether ZL IS greater than or less than ZO.
Description : State and explain the concept of transmission bandwidth.
Answer : Bandwidth is defined as the portion of the electromagnetic spectrum occupied by a signal We may also define the bandwidth as the frequency range over which as information signal is transmitted. Bandwidth is the ... to 15 KHZ. Therefore the bandwidth is(f2-f1) BW= f2 - f1= 15000-20=14980Hz
Description : Define critical frequency w.r. to wave propagation.
Answer : Define critical frequency w.r. to wave propagation.
Description : Explain virtual height with respect to wave propagation with neat sketch.
Answer : In ionization layer the incident wave refracts and bends down gradually than sharply. The incident and refracted rays follow paths that are exactly the same as they would have been if reflection had taken place from a surface located at a greater height called virtual height of this layer.
Description : Explain ground wave propogation with neat sketch.
Answer : Sketch- Explanationi) It consists of direct wave which travels near the ground from Transmitter to Receiver. ii) The electromagnetic wave leaves the transmitting antenna & remains close to earth surface ... . The ground wave is the path chosen when frequency in between 30 KHz & 3 MHz
Description : Why electromagnetic waves are said to be transverse wave ? Explain.
Answer : The electromagnetic waves are oscillations which propagate through free space. In electromagnetic waves the direction of electric field, magnetic field & propagation are mutually perpendicular. Hence electromagnetic waves are called as transverse wave.
Description : Describe the effect of ionosphere on sky wave propagation.
Answer : The Ionosphere is the upper portion of the atmosphere. The ultra violet radiation from the sun will ionize the upper layer of the atmosphere. In this layer free electrons and positive and negative ions are ... layer. Its Frequency Range is from 3 MHz to 30 MHz Polarization: Vertical.
Description : Explain the transverse electromagnetic waves in wave propagation.
Answer : 1. The electromagnetic waves are oscillations, which propagate through free space. 2. Em wave travel in free space at the speed of light. 3. Figure shows the simple EM wave, in which the direction of ... electromagnetic waves (TEM). Diagram:- Transverse electromagnetic wave(TEM) OR
Description : 1. Which nitrogen fixing bacteria is found in leguminuous plant? 2. A person to be qualified for standing in a panchayat election what age must have he attained? 3. Mirage is observed in ... coal reserves of India are found in which state? 20. Which Sultan provided employment to unemployeds?
Answer : Answer : 1. Rizobium 2. 21 years 3. Total reflection 4. Granite 5. Jahangir 6. Karnataka 7. Foreign Institutional Investors 8. Mycorrhizae 9. Barren Island 10. Aurobindo Ghosh 11. M. Hidayatullah 12. ... 16. New Delhi 17. Muscles ear lobe 18. Neelam Sanjiva Reddy 19. Jharkhand 20. Firoz shah Tughlaq
Description : Draw and label the circuit diagram of ratio detector
Answer : Draw and label the circuit diagram of ratio detector
Description : Explain with a neat diagram of ratio detector. Why limiter stage is not used before ratio detector.
Answer : With diode D2 reversed , O is positive with respect to b, so that Vab is a sum voltage rather than the difference it was in the discriminator it is now possible to connect a large capacitor ... of limiter stage due to large capacitor C5 .Hence, limiter stage is not used in ratio detector.