Description : Before using a volt-ohmmeter to measure resistance readings, you should _____________. A. replace all batteries B. test the insulation resistance of the leads C. make sure the test leads do not touch D. hold the leads together and 'zero' the meter
Last Answer : Answer: D
Description : Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointers to mid-scale B. change the meter's batteries C. center the meter's pointer at infinity D. short the test leads and calibrate the meter
Description : Before measuring an unknown resistance with an ohmmeter, you should _____________. A. adjust the meter's pointer to mid-scale B. short the test leads and calibrate the meter reading to 'zero' C. change the meter's batteries D. center the meter's pointer at infinity
Last Answer : Answer: B
Description : What two methods are used to compensate for the problems that cause low gain in an rf amplifier?
Last Answer : . RF transformers are used and the transistor is neutralized.
Description : Prior to taking a resistance reading with a volt-ohm-milliammeter, the 'zero' setting must be adjusted. After clipping the two leads together, you find the adjustment knob will not return the pointer ... range setting B. weak batteries C. a faulty zero ohms knob D. a faulty meter movement
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 : In troubleshooting a circuit in a console, you find that a resistor may be faulty. Which of the precautions listed must be observed when using an ohmmeter to carry out this test? A. Correct polarity ... D. The resistor's circuit must be de-energized and at least one end of the component isolated.
Description : A good choice of shunt resistance will place the indicating pointer near what part of the meter scale with a normal load?
Last Answer : Midscale.
Description : What structurally large, low-resistance conductor is connected in parallel with the meter movement to prevent damage?
Last Answer : Shunt.
Description : A small swamping resistance is connected in series with operating coil of a moving coil ammter in order to compensate for the effects of ____
Last Answer : temperature variation
Description : When using a multimeter for resistance measurements, it should be calibrated by clipping the loose ends of the leads together and _____________. A. setting the instrument pointer at 'zero' ohms B. ... the plus and minus terminals D. using a special purpose resistance measuring instrument (a bridge)
Last Answer : Answer: A
Description : A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected, this is caused by _____________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. capacitors inside the meter storing charges
Description : An ammeter reads slightly above 'zero' when its leads are disconnected, this is a result of ___________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. resistors inside the meter storing charges
Description : While troubleshooting a circuit in an engine room central control console, a resistor is suspected of being faulty. Which of the following precautions must be observed if an ohmmeter is to be used to ... of the component isolated. D. The meter case must be grounded prior to attaching the leads.
Last Answer : Answer: C
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.
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 : 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 : Current leads voltage by 90° (ICE)
Last Answer : Current leads voltage by 90° (ICE)
Description : In preparing to take insulation resistance readings on a main generator, the windings should be grounded for about 15 minutes prior to the test to _____________. A. allow accurate zeroing of the meter ... the windings D. help the windings to cool to the same temperature as the ground test connection
Description : If reading AC current with the illustrated device and unsure of the range as a precaution , the first step should be to _________. EL-0047 A. secure power and test for voltage B. disconnect the ... resistance and use Ohm's law to calculate current D. unable to safely measure current with the device
Description : To test fuses in an energized circuit, you should use a ____________. A. low voltage light bulb B. megohmmeter C. voltmeter D. resistance meter
Description : What is the difference between megger test equipment and contact resistance meter test instruments?
Last Answer : Megger test equipment used to measure cable electric resistance, conductor continuity, phase identification. Contact resistance meter test instruments used to measure low resistance like relays, contactors.
Description : When you are using an ohmmeter to test a transistor for leakage, what is indicated by a low, but not shorted, reverse resistance reading?
Last Answer : A leaking transistor
Description : What happens when a frequency meter is adjusted to the frequency of the signal being measured?
Last Answer : Power is absorbed by the frequency meter cavity; and a pronounced dip in power, at the output, will be observed.
Description : What is the main difference between a vu and a dB meter?
Last Answer : DB meters are used for measuring sine waves. Vu meters are used to measure the average value of complex waveforms.
Description : In a heterodyne-type frequency meter, what is the difference between the oscillator frequency and the unknown frequency?
Last Answer : Beat frequency.
Description : When is an optical power meter measurement recommended for conducting field measurements on installed optical fiber cables or cable plants?
Last Answer : When an installed optical fiber cable or cable plant is less than 50 meters in length.
Description : Why will a meter indicate more voltage at the battery terminal when the battery is out of a circuit than when the battery is in a circuit?
Last Answer : The internal (source) resistance of the battery will drop some of the voltage
Description : What condition produces the 10-kHz error signal generated by the metering bridge in the HP- 431C power meter?
Last Answer : An unbalance in the metering bridge.
Description : Besides setting up the meter for expected voltage ranges, what must be strictly observed when taking dc voltage readings?
Last Answer : Polarit
Description : What type of frequency meter is shown and what is the value indicated for each meter in figure 1-52?
Last Answer : A) Vibrating-reed, 60Hz. (B) Moving-disk, 58 Hz.
Description : What type of meter is shown and what is the value of the quantity being measured for each meter in figure 1-51?
Last Answer : (A) Megger (megohmmeter), infinity; (B) Wattmeter, 9.5 kilowatts (9,500 watts). (C) Watt-hour meter, 2.693 megawatt-hours 2,693 kilowatt-hours) (2,693,000 watt-hours).
Description : What meter reading is shown on each multimeter in each part of figure 1-50?
Last Answer : (A) 410 mA dc; (B) 3.9 mA ac; (C) -22 V dc; (D) 600 V ac; (E) 1.4 V ac; (F) 1.9 kohms
Description : What type of meter is shown and what is the value of the quantity being measured for each meter in figure1-49?
Last Answer : a. A dc ammeter, 90 mA dc b. A dc voltmeter, 200 V dc c. An ac voltmeter, 4.6 V ac d. An ohmmeter, 400 ohms
Description : What is the quantity shown on the watt-hour meter in figure 1-46?
Last Answer : 5.945 megawatt-hours, or 5,945 kilowatt-hours, or 5,945, 000 watt-hours.
Description : What electrical quantity is measured by a watt-hour meter?
Last Answer : Energy.
Description : What is the only use for the voltage sensitive meter movement?
Last Answer : High-voltage measurement.
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 electrical property is used by all the meter movements discussed so far?
Last Answer : Current.
Description : List three meter movements that can measure either ac or dc without the use of a rectifier.
Last Answer : Electrodynamic, moving vane, and hot-wire or thermocouple.