Description : How can a d’Arsonval meter movement be adapted for use as an ac meter?
Last Answer : By the use of a rectifier
Description : What is the effect of current flow through the coil in a d’Arsonval meter movement?
Last Answer : A magnetic field is generated around the coil and the attraction of this field with the permanent magnet causes the coil to move
Description : What type of meter movement is the d’Arsonval meter movement?
Last Answer : A permanent-magnet moving-coil meter movement used in most electrical and electronic meters.
Description : What modification is made to the D’Arsonval meter movement to enable the meter to measure voltage?
Last Answer : A multimeter (high resistance) is placed in series with the coil of the meter.
Description : What advantage is gained by using pole pieces with curved faces in the D’Arsonval meter movement?
Last Answer : Two-position and three-position.
Description : What component supplies restoring force to the coil of the D’Arsonval meter movement?
Last Answer : Hairspring.
Description : What component of the D’Arsonval meter movement completes the circuit for current flow to the coil?
Description : What is the primary advantage of the electrodynamometer type meter over the D’Arsonval-type meter?
Last Answer : The electrodynamometer-type meter can be used to measure both ac and dc currents.
Description : Which of the following electric meter movements uses a stationary permanent magnet and movable coil? A. D'Arsonval B. Electrodynamometer C. Moving iron-vane D. Inclined coil iron-vane
Last Answer : Answer: A
Description : A useful instrument for checking A.C. motor performance by measuring possible unbalanced currents is the _____________. A. hand or battery-operated megger B. vibrating-reed frequency meter C. hook-on voltmeter-ammeter D. D'Arsonval iron-vane probe
Last Answer : Answer: C
Description : If the pointer on a megger fails to return to 'zero' when not being used, the _____________. A. megger is out of calibration B. megger is operating normally C. hairsprings are burned out D. pointer probably stuck in that position
Last Answer : Answer: B
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 value does a meter movement react to (actually measure) when measuring ac?
Last Answer : Average value.
Description : What are two methods used to damp a meter movement?
Last Answer : As the coil moves through the field of the permanent magnet, a current is induced in the coil opposing the movement of the coil; and a vane can be attached to the coil and placed in the airtight chamber so that the movement of the vane opposes the movement of the coil.
Description : What is the limiting factor as to the amount of current an electrodynamometer meter movement can handle?
Last Answer : Size of spiral conducting.
Description : What components in an electrodynamometer-type meter movement produce the magnetic field?
Last Answer : Fixed coils.
Description : What structurally large, low-resistance conductor is connected in parallel with the meter movement to prevent damage?
Last Answer : Shunt.
Description : At what point on a meter movement are the most accurate readings taken?
Last Answer : Midscale.
Last Answer : An Aryton shunt is used to make a D'Arsonval galvanometer into a multi range ammeter.
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.
Description : Magnetic tape recorders can have up to three different heads installed. What are the three functions performed by a recorder's heads?
Last Answer : Record, reproduce, and erase.
Description : The control electronics component of a floppy or hard disk drive performs what three main functions?
Last Answer : a. Spins the disk at the correct speed. b. Moves the heads across the recording surface. c. Tells the write/read heads when to write data and when to read it.
Description : Hard disk drive transports contain the electromechanical parts that perform what three functions?
Last Answer : a. Rotates the hard disk platters. b. Writes data to and reads data from the disk platters
Description : What are the three functions of the magnetic heads on a magnetic recording device?
Last Answer : a. Record the signal onto the recording medium. b. Reproduce the signal from the recording medium. c. Erase the signal from the recording medium.
Description : What three functions does the transistor in a regenerative detector serve?
Last Answer : Oscillator, mixer, and detector.
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 electrical property is used by all the meter movements discussed so far?
Last Answer : Current.
Description : What value is indicated on the scale of an ac meter?
Last Answer : Effective value (rms).
Description : What is the purpose of a rectifier in a meter?
Last Answer : A rectifier changes alternating current to pulsating direct current and allows a dc meter to measure ac.
Description : What is one advantage of an out-of-circuit meter when it is compared with an in-circuit meter?
Last Answer : Out-of-circuit meters can be used on more than one electrical or electronic device.
Description : If a switch must be checked with power applied, what type of meter is used?
Last Answer : A voltmeter.
Description : What condition exists when the insertion of a meter into a circuit changes the operation of the circuit?
Last Answer : Meter-loading.
Description : (True or False) The larger the current required to produce full-scale deflection of the meter coil, the better the sensitivity of the meter.
Last Answer : False.