Description : A waveguide may also be terminated in a resistive load that is matched to the characteristic impedance of the waveguide. The resistive load is most often called a _____
Last Answer : Dummy resistor
Description : Why is the physical length of a coaxial cable transmission line shorter than its electrical length? A. Skin effect is less pronounced in the coaxial cable B. RF energy moves slower along the ... higher in the parallel feed line D. The characteristic impedance is higher in the parallel feed line
Last Answer : B. RF energy moves slower along the coaxial cable
Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω
Last Answer : C. 150 Ω
Description : Transmission lines when connected to antenna have A. capacitive load B. resistive load whose resistance is less than characteristics impedance C. resistive load at the resonant frequency D. resistive load whose resistance is greater than the characteristic impedance of the line
Last Answer : C. resistive load at the resonant frequency
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.
Last Answer : Solution :
Description : What is the meaning of the term velocity factor of a transmission line? A. The ratio of the characteristic impedance of the line to the terminating impedance B. The index of shielding for coaxial ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.
Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.
Description : What is the meaning of the term velocity factor of a transmission line? A. The index of shielding for coaxial cable B. The velocity of the wave on the transmission line multiplied by the velocity of ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum
Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum
Description : Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity
Last Answer : B. Velocity factor
Description : If the terminating impedance is exactly equal to the characteristic impedance of the transmission line the return loss is ___________. A. zero B. one C. infinite D. None of these
Last Answer : C. infinite
Description : In swept-frequency testing the impedance of a transmission line, what electrical characteristic is actually being measured?
Last Answer : Swr on the transmission line.
Description : Short-circuited stubs are preferred to open-circuited stubs because thelatter are a. more difficult to make an connect b. made of a transmission line with a different characteristic impedance c. liable to radiate
Last Answer : c. liable to radiate
Description : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.
Last 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 : The input impedance of a short circuited loss less transmission line of characteristic impedance 50 Ohm is
Last Answer : Capacitive
Description : A transmission line is terminated at its characteristic impedance. The reflection coefficient is (a) 1 (b) –1 (c) 0 (d) ∞
Last Answer : A transmission line is terminated at its characteristic impedance. The reflection coefficient is 0
Description : Two transformers of identical voltages but different capacities are operated in parallel, for satisfactory load sharing: a) Impedances should be equal b) Per unit impedance must be equal c) per unit impedance and X/R ratio must be equal d) Impedance and X/R ratio must be equal
Last Answer : Ans: C
Description : Two transformers operating in parallel will share the load depending upon their (A) Rating. (B) Leakage reactance. (C) Efficiency. (D) Per-unit impedance.
Last Answer : Ans: A Transformers having higher kVA rating will share more load.
Description : When two generators are on the line and are sharing the load equally, they are said to be operating in _____________. A. frequency B. series C. parallel D. resonance
Last Answer : Answer: C
Description : A properly matched transmission line has a loss of 1.5 dB/100m. if 10 W is supplied to one end of the line, how many watts reach the load, 27 m away? A. 10 W B. 7.2 W C. 9.9 W D. 9.1 W
Last Answer : D. 9.1 W
Description : Transmission line must be matched to the load to A. transfer maximum voltage to the load B. transfer maximum current to the load C. reduce the load current D. transfer maximum power to the load
Last Answer : D. transfer maximum power to the load
Description : The standing wave ratio is equal to ________ if the load is properly matched with the transmission line. A. 1 B. 50 C. 10 D. 2
Last Answer : A. 1
Description : The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance ... input power to below its critical level. D. an impedance mismatch between the load and the line.
Last Answer : D. an impedance mismatch between the load and the line.
Description : Which of the following characterizes a properly terminated transmission line? A. The line loss is minimum. B. The standing wave ratio is minimum. C. The input impedance is twice the load impedance. D. The standing wave ratio is one.
Last Answer : D. The standing wave ratio is one.
Description : Termination means A. result of disconnecting a line from a transmitter B. result of cutting both ends of a conductor C. looking back impedance of a line with no load D. load connected to the output end of a transmission line
Last Answer : D. load connected to the output end of a transmission line
Description : What will be the reflection coefficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ? (a) Zero (b) Unity (c) Infinity (d) None of the above
Last Answer : (a) Zero
Description : When the load on a transmission line is equal to the surge impedance loading (a) The receiving end voltage is less than the sending end voltage (b) The sending end voltage is less than the ... is more than the sending end voltage (d) The receiving end voltage equal to the sending end voltage
Last Answer : When the load on a transmission line is equal to the surge impedance loading The receiving end voltage equal to the sending end voltage
Description : What is the characteristic impedance of a single wire with a diameter d= 0.25 mm placed at the center between grounded parallel planes separated by 1 mm apart. The wire is held by a material with a velocity factor of 0.75. A. 85 Ω B. 63 Ω C. 50 Ω D. 75 Ω
Last Answer : D. 75 Ω
Description : Calculate characteristic impedance (Zo) for parallel and co-axial cables.
Last 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 : Two transformers having the same p.u. impedance connected in parallel share the connected load (A) equally (B) in proportion to the respective ratings (C) in proportion to the voltage ratio (D) in proportion to the zero phase displacement
Last Answer : Two transformers having the same p.u. impedance connected in parallel share the connected load in proportion to the respective ratings
Description : Which of the electrical properties listed will always be the same for each component in a parallel circuit? A. Impedance B. Current C. Resistance D. Voltage
Last Answer : Answer: D
Description : Longitudinal vibrations are said to occur when the particles of a body moves A Perpendicular to its axis B Parallel to its axis C In a circle about its axis D None of the mentioned
Last Answer : B Parallel to its axis
Description : Longitudinal vibrations are said to occur when the particles of a body moves (A) Perpendicular to its axis B (B) Parallel to its axis (C) In a circle about its axis (D) None of the mentioned
Last Answer : (B) Parallel to its axis
Description : Longitudinal vibrations are said to occur when the particles of a body moves a) perpendicular to its axis b) parallel to its axis c) in a circle about its axis d) none of the mentioned
Last Answer : b) parallel to its axis
Description : What will happen if transformer in parallel connection have different percentage impedance or X/R ratio ?
Last Answer : A difference in the ratio of the reactance value to resistance value of the per unit impedance results in a different phase angle of the currents carried by the two paralleled transformers; one ... of the combined output. Hence, the real power will not be proportionally shared by the transformers.
Description : What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum? A. Velocity factor B. Characteristic impedance C. Surge impedance D. Standing wave ratio
Last Answer : A. Velocity factor
Description : What is the characteristic impedance of a coaxial line with the following data: inner diameter = 0.2 in., center conductor diameter = 0.06 in., insulation = Teflon. A. 200Ω B. 75Ω C. 50Ω D. 150Ω
Last Answer : C. 50Ω
Description : What is the characteristic impedance of a two-wire line with the following data: diameter = 0.023in., spacing =0.5 in., insulation = PE.? A. 300Ω B. 250Ω C. 305Ω D. 301Ω
Last Answer : D. 301Ω
Description : What symbol is used to designate the characteristic impedance of a line, and what two variables does it compare?
Last Answer : Z0 and it is the ratio of E to I at every point along the line.
Description : A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is: (1) 4000 Ω (2) 400 Ω (3) 40 Ω (4) 4 Ω
Last Answer : A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is: 400 Ω
Description : A loss less line of characteristic impedance Z0 is terminated in pure reactance of –jZ0 value. VSWR is (1) 10 (2) 2 (3) 1 (4) Infinity
Last Answer : A loss less line of characteristic impedance Z0 is terminated in pure reactance of –jZ0 value. VSWR is Infinity.
Description : Polar moment of inertia is a.Applicable to masses whereas moment of inertia is applicable to area only b.The moment of inertia for an area ralative to a line or axis which is out the plane of area ... The moment of inertia for an area relative to a line or axis perpendicular to the plane of the area
Last Answer : e. The moment of inertia for an area relative to a line or axis perpendicular to the plane of the area
Description : is this statement true or falseTwo lines that are perpendicular to the same line are parallel.?
Last Answer : 1
Description : is this statement true or falseIf two lines are perpendicular to the same line, then they are parallel to each other.?
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth. B. The magnetic field is parallel to the earth. C. Both the electric and magnetic fields are horizontal D. Both the electric and magnetic fields are vertical
Last Answer : A. The electric field is parallel to the earth.
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth B. Both the electric and magnetic fields are vertical C. Both the electric and magnetic fields are horizontal D. The magnetic fields is parallel to the earth
Last Answer : A. The electric field is parallel to the earth
Description : A parallel polarized wave is incident from air into paraffin having relative permittivity 3, the value of its Brewster angle is: (1) 0° (2) 30° (3) 45° (4) 60°
Last Answer : A parallel polarized wave is incident from air into paraffin having relative permittivity 3, the value of its Brewster angle is:60°
Description : A load with an impedance of 440 ohms is connected across the secondary of the transformer illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given
Last Answer : Answer: B
Description : A load with an impedance of 440 ohms is connected across the secondary of the device illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given
Description : When troubleshooting electronic equipment, you should use a high impedance multimeter ________________. A. to prevent excess current flow through the meter that would damage it B. for AC measurements only ... being tested D. so as not to load down the circuit and obtain erroneous voltage readings
Description : What determines the velocity factor in a transmission line? A. The termination impedance B. The line length C. Dielectrics in the line D. The center conductor resistivity
Last Answer : C. Dielectrics in the line