Description : Why do we close the switch at 11 o'clock and not at 12 o' clock?
Last Answer : When the synchroscope is approaching 12 o'clock the "slip" (differential) between the sine waves is approaching minimum (slip is zero when the synch'scope is at 12 o'clock) and the voltage differential between ... delay to close, by doing at 11 o'clock, we are achieving closing close to 12 o'clock.
Description : As shown in the illustration, which of the listed actions of the synchroscope pointer is occurring? EL-0002 A. Revolving slowly in the slow direction. B. Revolving rapidly in the slow direction. C. ... stationary at the 12 o'clock position since the leading edges of the A phases are in phase.
Last Answer : Answer: C
Description : When two AC generators are being paralleled, the breaker should be closed with the synchroscope pointer rotating in the ____________. A. 'slow' direction, just before the 12 o'clock position B. 'fast' ... just before the 12 o'clock position D. 'slow' direction, just after the 12 o'clock position
Description : The devices labeled 'L' in the illustration are _________. EL-0003 A. load lights indicating that the generator breaker is closed and the generator is supplying power to the main bus B. ... o'clock position the lights are at their dimmest or out indicating the the generators are in phase
Last Answer : Answer: D
Description : Which of the synchroscope illustrations depicts the appropriate direction of rotation and position for closing the circuit breaker when paralleling AC generators? EL-0053 A. A B. B C. C D. D
Description : When paralleling two alternators the synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates the ____________. A. alternator voltages ... alternator is in phase with the bus voltage D. synchroscope pointer is defective or broken
Description : An AC generator panel is fitted with both synchronizing lamps and a synchroscope. When the synchroscope pointer reaches the noon position, one synchronizing light is bright and the other is dark. This ... sequence is incorrect C. the phase sequence is correct D. the generator breaker may be closed
Last Answer : Answer: B
Description : You are attempting to parallel two AC generators, and the synchroscope pointer is revolving fast in the clockwise direction. This indicates that the frequency of the incoming machine is _____________. A. higher ... at any pointer position D. the same as the bus frequency but out of phase with it
Last Answer : Answer: A
Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming ... hazardous condition will be created by the incoming machine being at a higher frequency than the bus
Description : You are attempting to parallel two AC generators, and the synchroscope pointer is revolving in the fast direction. This indicates that the frequency of the incoming machine is _____________. A. higher ... the same as the bus frequency and the circuit breaker may be closed at any pointer position
Description : You are paralleling two alternators. The synchronizing lamps grow dim and are totally darkened as the synchroscope pointer approaches the 0° position. This indicates that the ____________. A. alternator ... be closed C. incoming alternator is running too slowly D. synchroscope is defective or broken
Description : You are attempting to parallel two AC generators and the synchroscope pointer is revolving slowly in the fast direction. You should _____________. A. use the governor control switch to adjust the incoming ... the 0° position D. use the field rheostat to adjust the speed of the incoming machine
Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0° prior to closing the circuit breaker. This indicates ___________. A. the frequency of ... be closed after breaker has been reset D. there is an existing cross current between generators
Description : You are attempting to parallel two AC generators and the synchroscope pointer is revolving in the slow direction. This indicates that the frequency of the incoming machine is _____________. A. higher than ... same as the bus frequency, and the circuit breaker may be closed at any pointer position
Description : As 'Wheel' is related to 'Vehicle' similarly 'Clock' is related to what? (A) Needle(B) Nail(C) Stick(D) Pin(E) None of these
Last Answer : (A) Needle
Description : Fortransmission-line loadmatchingover a range offrequencies,itisbesttouse a a. balun b. broadband directional coupler c. double stub d. single stub of adjustable position
Last Answer : c. double stub
Description : When 2,4 and 6 ohms resistor are connected in parallel their resultant equivalent resistance will be A. 12ohm b. 11/12ohm C. 12/11ohm d. None
Last Answer : C. 12/11ohm
Description : What is the resistance value indicated on the multimeter scale illustrated, if the range switch is set at R X 100, and the needle is at the position indicated by the letter 'R'? EL-0047 A. 6.0 ohms B. 162.5 ohms C. 600 ohms D. 16,250 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'F'? EL-0047 A. 0.6 ohms B. 6 ohms C. 9.6 ohms D. .38 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'D'? EL-0047 A. 7.8 ohms B. 8 ohms C. 3.6 ohms D. .36 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'R'? EL-0047 A. 6 ohms B. 6.8 ohms C. 1.7 ohms D. 167 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'X'? EL-0047 A. 8 ohms B. 6.2 ohms C. 1.57 ohms D. 150 ohms
Description : All electrical appliances are connected in parallel to each other between the main line and neutral wire to get a. same current b. same current and potential difference c. different current but same potential difference d. different current and potential differences
Last Answer : c. different current but same potential difference
Description : The region where the Lyman series contains the wavelength 1∕ λ = RH [1/ 12 – 1/ n2 ] is a) visible region b) infrared region c) ultraviolet region d ) none of these
Last Answer : c) ultraviolet region
Description : An electric iron is marked 20 volts 500W. The units consumed by it in using if for 24 hours will be a. 12 b. 24 c. 5 d. 1100
Last Answer : a. 12
Description : A charge of 10μC and 14.4 μC are 12 cm apart, the force between them is: (a) 9 × 105 N (b) 9 × 107 N (c) 90 N (d) 108 × 107 N
Last Answer : (c) 90 N
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 100, and the needle is at the position indicated by the letter 'Y'? EL-0047 A. 220 ohms B. 240 ohms C. 2,400 ohms D. 24,000 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'A'? EL-0047 A. 10 ohms B. 100 ohms C. 200 ohms D. 1,000 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'C'? EL-0047 A. 1.3 ohms B. 4.8 ohms C. 13 ohms D. 121 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1, and the needle is at the position indicated by the letter 'B'? EL-0047 A. 1.45 ohms B. 7.2 ohms C. 37 ohms D. 70 ohms
Description : What is the resistance value indicated by the multimeter scale illustrated, if the range switch is set at R X 1 and the needle is at the position indicated by the letter 'Y'? EL-0047 A. 2.2 ohms B. 24 ohms C. 240 ohms D. 2,400 ohms
Description : In order to be effective, Percutaneous Transluminal Coronary Angioplasty (PTCA) must be performed within what time frame, beginning with arrival at the emergency department after diagnosis of myocardial ... during which streptokinase will not be used again in the same patient for acute MI.
Last Answer : a) 60 minutes The sixty minute interval is known as “door to balloon time” for performance of PTCA on a diagnosed MI patient.
Description : Whichofthe followingterms describesthe reason thatlightisrefractedat different angles? a. Photon energy changes with wavelength b. Light is refracted as a function of surface smoothness c. The angle is determined partly by a and b d. The angle is determined by the index of the materials
Last Answer : d. The angle is determined by the index of the materials
Description : Electromagneticwaves are refractedwhen they a. pass into a medium of different dielectric constant b. are polarized at right angles to the direction of propagation c. encounter a perfectly conducting plane d. pass through a small slot in a conducting plane
Last Answer : a. pass into a medium of different dielectric constant
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 : What is a relay? How is it different from a magnetic contactor?
Last Answer : Contactor is a heavy duty switch whereas the relay is light duty switch. Relays can be as simple as 12 V DC solenoids with 12 V, 0.5 A rated contacts. They are used to detect faults on the power system and signal a local or remote switching device (breaker) to trip the circuit.
Description : Why is it different from that for welding?
Last Answer : It is higher as the ignition requires break down of air gap for park to occur. The air breaks down at this high voltage of 10kV. Therefore, it is higher than normal welding voltage.
Description : The fact that the spectrum of any element contains wavelengths that exhibit definite regularities was ` utilized in the second half of the _______in identifying different elements. a) 16th century b) 17th century c) 18th century d) 19th century
Last Answer : d) 19th century
Description : Tick the wrong statement. a) Velocity of light is independent of the motion of the observer. b) Velocity of light in free space is the same in all directions. c) Velocity of light in free space is different in different directions. d) Absolute motion or absolute rest is meaningless to talk about
Last Answer : c) Velocity of light in free space is different in different directions
Description : The Si unit of mutual inductance and self inductance is: a.same b. different c. no unit d. a & b
Last Answer : b. different
Description : State different types of electrical signal and draw all types of waveforms.
Last Answer : Types of electrical signals 1) Sine wave 2) Triangular wave 3) Square wave Waveforms
Description : The use of permanent magnets is. not made in (a) magnetoes (6) energy meters (c) transformers (d) loud-speakers
Last Answer : (c) transformers
Description : Magnetising steel is normals difficult because (a) it corrodes easily (6) it has high permeability (c) it has high specific gravity (d) it has low permeability
Last Answer : (d) it has low permeability
Description : A permeable substance is one (a) which is a good conductor (6) which is a bad conductor (c) which is a strong magnet (d) through which the magnetic lines of force can pass very easily
Last Answer : (d) through which the magnetic lines of force can pass very easily
Description : In the phenomenon of Laser production, atom can reside in the excited state only for a) 10-6 s b) 10-7 s c) 10-8 s d) 10-9 s
Last Answer : c) 10-8 s
Description : The amount of energy required to completely remove an electron from the first Bohr orbit is a) 13.6 MeV b) 13.6 eV c) 1.36 MeV d) 1.36 eV
Last Answer : b) 13.6 eV
Description : In transistor, the base region is of the order of _______ (a) 10-5 m (b) 10-2 m (c) 10-8 m (d) 10-6 m
Last Answer : d) 10-6 m
Description : The potential barrier for germanium is _______ (a) 0.6 V (b) 0.2 V (c) 0.3 V (d) 0.5 V
Last Answer : (c) 0.3 V
Description : he substances of conductivity of the order of 10–6 – 10–4 (m)–1 are : a) Insulators b) Super conductors c) Semiconductors d)Good conductors
Last Answer : d)Good conductors
Description : An α particle moves perpendicular to a constant magnetic field of strength 1.2 T in a circular path of radius 0.7 m. The speed of α particle in ms-1 is ______________ a) 2.7 × 107 b) 2.6 × 107 c) 3.2 × 107 d) 2.0 × 107
Last Answer : a) 2.7 × 107