Description : In cables the charging current (a) lags the voltage by 90° (b) leads the voltage by 90° (c) lags the voltage by 180° (d) leads the voltage by 180°
Last Answer : (b) leads the voltage by 90°
Description : No load current in a transformer: (A) lags the applied voltage by 90° (B) lags the applied voltage by somewhat less than 90° (C) leads the applied voltage by 90° (D) leads the applied voltage by somewhat less than 90°
Last Answer : Ans: B The primary input current under no load conditions has to supply (i) iron losses in the core i.e hysteresis loss and eddy current loss (ii) a very small amount of Cu loss in the primary (there being no Cu loss in secondary as it is open)
Description : The vector representing acceleration on a vector diagram for a harmonic motion A) Lags the displacement vector by 90° B) Lags the displacement vector by 180° C) Leads the displacement vector by 90° D) Leads the displacement vector by 180°
Last Answer : C) Leads the displacement vector by 90°
Description : The velocity vector in a vector diagram for a harmonic motion A) Lags the displacement vector by 180° B) Leads the displacement vector by 90° C) Lags the displacement vector by 90° D) Leads the displacement vector by 180°
Last Answer : B) Leads the displacement vector by 90°
Description : The leads to the primary and the high-voltage secondary windings of a power transformer usually are of what color?
Last Answer : Primary leads-black; secondary leads red.
Description : One important difference between wye-connected and delta-connected generators is that delta connections have ____________. A. line voltages equal to the vector sum of the phase voltages B. phase voltages 90° ... C. line current equal to the phase current D. line voltage equal to the phase voltage
Last Answer : Answer: D
Description : The arc voltage produced in A.C. circuit breaker is always (a) in phase with the arc current (b) lagging the arc current by 90" (c) leading the arc current by 90° (d) none of the above
Last Answer : (a) in phase with the arc current
Description : Which of the following precautions should be taken when troubleshooting various power circuits using a common solenoid-type mechanical voltage tester (wiggins)? A. Never use this tester on circuits greater ... voltage expected in the circuit in order to prevent damage from an off-scale reading.
Last Answer : Answer: A
Description : To properly use a hook-on-type volt/ammeter to check current flow, you must FIRST _____________. A. de-energize the circuit to allow connection of the instrument in series B. hook the jaws ... test leads to the appropriate terminals D. short the test leads and calibrate the instrument to zero
Last Answer : Answer: B
Last Answer : If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is 10°.
Description : When you zero a synchro with a synchro tester, what is indicated by a jump in the synchro tester's dial when the S1 and S3 leads are momentarily shorted?
Last Answer : The synchro under test is not on electrical zero.
Description : What two receiver leads are reversed to reverse the rotor's direction of rotation?
Last Answer : 1 and S3.
Description : What leads in a simple synchro system are connected to the ac power line?
Last Answer : The rotor leads.
Description : What is the purpose of the spring or wire around the leads of a new MOSFET?
Last Answer : To prevent damage from static electricity.
Last Answer : By pushing it gently out of the board.
Description : When removing the component, under what circumstances may component leads be clipped?
Last Answer : If the component is known to be defective or if the board may be damaged by normal desoldering.
Description : In what direction are component leads clinched on single and double-sided boards?
Last Answer : In the direction of the run.
Description : Leads are formed approximately how many degrees from their major axis?
Last Answer : 90 degrees
Description : How is oxide removed from pads and component leads?
Last Answer : A fine abrasive.
Description : . A full-scale deflection on an ohmmeter scale indicates what resistance between the leads?
Last Answer : Zero.
Description : A full-scale deflection on an ohmmeter scale indicates what resistance between the leads?
Description : How do you compensate for the resistance of the test leads of a meter?
Last Answer : . By zeroing the meter with the test leads shorted.
Description : What is the name of the device that provides an increase in current, voltage, or power of a signal without appreciably altering the original signal?
Last Answer : Amplifier.
Description : Which quantity (voltage or current) determines the intensity of an electrical shock?
Last Answer : Current.
Description : Circuits which maintain constant voltage or current outputs are called dc voltage or dc current ___.
Last Answer : Regulators.
Description : . A non-resonant line is a line that has no standing waves of current and voltage on it and is considered to be flat. Why is this true?
Last Answer : The load impedance of such a line is equal to Z0.
Description : How does transit time affect the relationship of the grid voltage and the plate current at high frequencies?
Last Answer : Transit time causes the grid voltage and plate current to be out of phase
Description : What is the relationship of current to voltage in a circuit?
Last Answer : current increases as voltage increases.
Description : What is the phase relationship between current and voltage in an inductor?
Last Answer : Current lags voltage by 90° (ELI).
Description : how is (a) the current through R2 and (b) the voltage drop across R2 computed?
Last Answer : (a) By adding the bleeder current (IR1) and the current through load 1(b) By subtracting the voltage of load 1 from the voltage of load 2.
Description : If the source voltage for the voltage divider in question 50 supplies 150 volts, what is the total current through the voltage divider?
Last Answer : 495 mA.
Description : If a voltage divider is required for a load that will use 450 mA of current, what should be the value of bleeder current?
Last Answer : 45 mA rule-of-thumb.
Description : A series circuit consists of two resistors in series. R1 = 25 ohms and R2 = 30 ohms. The circuit current is 6 amps. What is the (a) source voltage, (b) voltage dropped by each resistor, (c) total power, and (d) power used by each resistor?
Last Answer : (a) 330 volts. (b) E1 = 150 volts. E2 = 180 volts. (c) 1.98 kilowatts. (d) P1 = 900 watts. P2 = 1.08 kilowatts component but in a parallel circuit total current divides among the available paths.
Description : What would the source voltage (ES) in figure 3-39 be if the current through R2 were 2 milliamps?
Last Answer : 60 volts.
Description : If the current was increased to 4 amps, what would be the voltage drop across each resistor in the circuit described in question 17?
Last Answer : E1 = 80 volts. E2 = 240 volts. E3 = 320 volts
Description : A series circuit consisting of three resistors has a current of 3 amps. If R1 = 20 ohms, R2= 60 ohms, and R 3 = 80 ohms, what is the (a) total resistance and (b) source voltage of the circuit?
Last Answer : (a) 160 ohms. (b) 480 ohms
Description : Using the graph in figure 3-7, what is the approximate value of current when the voltage is 12.5 volts?
Last Answer : 1.25 amperes.
Description : According to Ohm’s law, what happens to circuit current if the applied voltage (a) increases, (b) decreases?
Last Answer : (a) Current increases (b) Current decreases
Description : How does the current-diode detector differ from the voltage-diode detector?
Last Answer : The current-diode detector is in parallel with the input and load.
Description : What is a disadvantage of a direct-current system with respect to supply voltage?
Last Answer : the dc voltage must be generated at the level required by the load.
Description : What are the voltage and current ratings for a fuse designated
Last Answer : a. 125 volts or less, 1/16 ampere b. 250 volts or less, .15 ampere
Description : What are the voltage, current, and time delay ratings for a fuse with the designation
Last Answer : a. 125 volts or less, 1.5 amperes, delay b. 250 volts or less, 1/8 ampere standard
Description : What type of meter movement reacts to voltage rather than current?
Last Answer : Electrostatic.
Description : How is it possible to use a current sensitive meter movement to measure voltage?
Last Answer : Since the resistance of a meter movement remains the same as the pointer is deflected, the amount of current through the movement is proportional to the voltage applied. Therefore, only the scale of the movement must be changed.
Description : What is the term used to identify the points of minimum current and minimum voltage on an antenna?
Last Answer : Current and voltage nodes.
Description : What is the term used to identify the points of high current and high voltage on an antenna?
Last Answer : Current and voltage loops.
Description : In order to determine whether or not 'fuse 2' shown in the illustration is defective, you should connect the voltage tester leads across points _____________. EL-0062 A. AC B. AD C. BC D. BD
Description : In order to determine whether or not 'Fuse 1', shown in the illustration is defective, you should connect the voltage tester leads across points _____________. EL-0062 A. AC B. AD C. BC D. BD
Last Answer : Answer: C
Description : In the illustrated circuit, if the input to leads 'B' and 'Y' was 24 VDC the output between 'A' and 'X' will be _________. EL-0069 A. 24 VDC B. 22.8 VDC, 24 VDC minus the 1.2 VDC voltage drop across two diodes C. undeterminable without knowing the turns ratio of the transformer D. 0 VDC
Description : You are reconnecting a three-phase induction motor to the supply line. To prevent possible damage to the load, due to the wrong direction of rotation, you should ____________. ... supply line phase sequence and motor rotation with appropriate indicators, then connect correspondingly marked leads