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 : An instantaneous-trip-type fuse will _____________. A. open as soon as the load current exceeds its set point B. allow a preset delay between overcurrent and melting C. open a circuit by using a time delay element with a magnetic trip D. reset itself when the overcurrent is corrected
Last Answer : Answer: A
Description : . If the power distribution system shown in figure 2-22 uses selective tripping, what is the time delay rating for each of the circuit breakers shown?
Last Answer : CB1-long time delay; CB2, CB3-short time delay; CB4 through
Description : How could you check a 1/500-ampere fuse with an ohmmeter?
Last Answer : Use a resistor in series with the fuse when you check it with the ohmmeter.
Description : Shading coils are installed on AC full-voltage starters to _____________. A. eliminate contact chatter B. dissipate opening contact arcs C. delay current build up in the holding coil D. protect the motor windings from momentary starting current overload
Description : What are the three time delay ratings for circuit breakers?
Last Answer : Instantaneous, short time delay, and long time delay.
Description : Delay differences between the source wavelengths occur as the optical signal propagates along the fiber. What is this called?
Last Answer : Differential group delay t(l).
Description : Using a fuse whose rating is higher than necessary ________. A. endangers the apparatus it is supposed to protect B. reduces the possibility of short circuits C. increases the efficiency of the equipment by allowing more current to be used D. wastes money because they are more expensive
Description : To protect wiring from excessive passing of current is A. voltmeter B. fuse C. galvanometer D. resistanc
Last Answer : fuse
Description : The main function of a fuse is to (a) protect the line (b) open the circuit (c) protect the appliance (d) prevent excessive currents (e) none of the above
Last Answer : (d) prevent excessive currents
Description : A fuse is placed in series with the cireuit to protect against a. high power b. high voltage c. high current d. over heating
Last Answer : d. over heating
Description : If the fuse shown on the schematic (figure 3-10) opens, what lights will operate?
Last Answer : Only the brake lights.
Description : List the safety precautions to be observed when replacing a fuse.
Last Answer : Be sure the power is off in the circuit and the circuit is discharged before replacing a fuse. Use an identical replacement fuse if possible. Remove any corrosion from the fuseholders before replacing the fuses.
Description : What two things should you check before replacing a fuse?
Last Answer : Check for the proper type of replacement fuse and proper fit.
Description : You have just checked a 1/500-ampere fuse with an ohmmeter and find it is open. Checking the replacement fuse shows the replacement fuse is open also. Why would the replacement fuse indicate open?
Last Answer : The ohmmeter causes more than 1/500 ampere through the fuse when you check the fuse, thus it opens the fuse.
Description : You have just checked a fuse with an ohmmeter and find that the fuse is shorted. What should you
Last Answer : Put it back in the circuit. A good fuse will have zero ohms of resistance.
Description : What are three methods for determining if a fuse is open?
Last Answer : Visual inspection, indicators, and using a meter
Description : What is the new military designation for a fuse with the old military designation F05A20ROB?
Last Answer : F05B32V20A.
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 does the voltage rating of a fuse indicate?
Last Answer : The ability of the fuse to quickly extinguish the arc after the fuse element melts and the maximum voltage that cannot jump across the gap of the fuse after the fuse opens.
Description : What does the current rating of a fuse indicate?
Last Answer : The amount of current the fuse will allow without opening.
Description : In a cartridge-type fuse, the metal element is contained in a ___________________. A. porcelain window B. thermal cut out C. fiber tube D. flasher device
Last Answer : Answer: C
Description : What is the most common type of nonmetallic material used to protect wires and cables?
Last Answer : Fibrous Braid.
Description : A device which is used to limit the current in an electrical circuit is called a - (1) Grid (2) Fuse (3) Hub (4) Conductor
Last Answer : (2) Fuse Explanation: A fuse places a limit on the amount of current that can be drawn by an electric circuit by opening (blowing or melting) when the current exceeds a preset limit. This protects the circuit and the surroundings from fire or damage in the case of an overload or short circuit.
Description : A fuse will 'blow' if _____________. A. an electric motor is stopped suddenly by opening a switch B. the flow of current to the protection device is reversed C. the electrical current exceeds the rated value of the fuse D. unequal resistors are connected in parallel
Description : ECE Board Exam March 1996 A device to be connected across the headset in telephone receivers to reduce the effects of acoustic shock. A. Ground B. Two rectifiers in parallel with opposite polarities C. Protector D. Fuse
Last Answer : B. Two rectifiers in parallel with opposite polarities
Description : A device which is used to limit the current in an electrical circuit is called a (1) Grid (2) Fuse (3) Hub (4) Conductor
Last Answer : Fuse
Description : Jack is in charge of a project team. Due to an unexpected project change, some issues with the project have come up. Two key team members, Samantha and Felix, are arguing their ... concerns through conflict resolution. e. Delay this issue for now until it becomes a significant conflict.
Last Answer : a. Confront the problem early, and invite both Samantha and Felix to private meetings.
Description : What device sweeps a band of frequencies to determine frequencies and amplitudes of each frequency component?
Last Answer : Spectrum analyzer.
Description : A computer or device that uses 8-bit ASCII or EBCDIC will use how many bits to store each character?
Last Answer : Nine.
Description : How do the tape guides on a tape reeling system protect the tape from damage during operation?
Last Answer : They keep the tape straight with respect to both the supply and take-up reels and the magnetic heads.
Description : When packaging tape reels or cartridges for shipping, what are four rules you should follow to protect the tape reels from impact and vibration?
Last Answer : a. Package reels so they’re supported by their hub, b. use reel bands, c. package reels in vertical position, d. package tape cartridges in their shipping cases.
Description : List four rules you should follow when storing magnetic tape to protect it from damage.
Last Answer : a. Make sure the tape is wound properly on the reel hub, b. store tapes vertically, c. keep storage area at right temperature and humidity, d. store away from equipment that generates stray magnetic fields.
Description : How are circuits protections devices connected to the circuit they are intended to protect and why are they connected in this way?
Last Answer : In series, so total current will be stopped when the device opens.
Description : When you are testing an inductor with a Hay bridge, the characteristics of the inductor are compared with what type of device?
Last Answer : A standard capacitor
Description : What type of device is used to extend the current measuring capability of electrodynamic wattmeters?
Last Answer : Current transformers.
Description : The varactor is a pn junction that acts as what type of electronic device?
Last Answer : Variable capacitor.
Description : How would one squeeze more channels of communication into TDM frames of standard length? A. Shorten the time delay for each channel B. Raise the amplitude C. Add modulators D. Remove the synchronizing pulses
Last Answer : A. Shorten the time delay for each channel
Description : A 4-bit synchronous counter uses flip-flops with propagation delay times of 15 ns each. The maximum possible time required for change of state will be (A) 15 ns. (B) 30 ns. (C) 45 ns. (D) 60 ns.
Last Answer : Ans: A 15 ns because in synchronous counter all the flip-flops change state at the same time.
Description : Suppose transmission rate of a channel is 32 kbps. If there are ‘8’ routes from source to destination and each packet p contains 8000 bits. Total end to end delay in sending packet P is _____. a. 2 sec b. 3 sec c. 4 sec d. 1 sec
Last Answer : a. 2 sec
Description : Each flip-flop in a 4-bit ripple counter introduces a maximum delay of 40 n sec. The maximum clock frequency is (a) 2.65 MHz (b) 6.25 MHz (c) 5.26 MHz (d) 6.52 MHz
Last Answer : Each flip-flop in a 4-bit ripple counter introduces a maximum delay of 40 ns. The maximum clock frequency is 6.25MHz. nff * Tdelay = 4*40 =160ns so, max. frequency = 1/ (200*10-9 ) = 6.25MHz
Description : The purpose of a motor undervoltage protection device is to _____________. A. prevent high armature current when power is restored B. start the motor at a very low voltage C. trip the load off the motor in case of fire D. protect personnel from low voltage shocks
Description : . Name the safety device used to protect the boiler, when the water level falls below a minimum level. (A) Blow down valve (B) Blow off cock (C) Fusible plug (D) Safety valve
Last Answer : (C) Fusible plug
Description : A firewall is a a. wall built to prevent fires from damaging a corporate intranet b. security device deployed at the boundary of a company to prevent unauthorized physical access c. ... it from unauthorized access d. device to prevent all accesses from the internet to the corporate intranet
Last Answer : c. security device deployed at the boundary of a corporate intranet to protect it from unauthorized access
Description : A teacher is introducing a new subject when meeting the class for the first time it would be best to Options: A) Begin with the first lesson without delay B) Give a class a ... of the previous grades D) Concentrate on identifying potential trouble-makers and leaders of the classroom mischief
Last Answer : B) Give a class a broad outline of the subject
Description : If you are required to monitor the speed of a device with a stroboscope over an extended period of time, what step should be taken to prolong the life of the flasher tube?
Last Answer : Monitor a submultiple frequency to prolong the flasher-tube life.
Description : When a constitutional amendment bill goes to the President, he – (1) can withhold his assent (2) can return it to the Parliament for reconsideration (3) can delay it for not more than six months (4) is bound to give his assent
Last Answer : (4) is bound to give his assent Explanation: All bills passed by the Parliament can become laws only after receiving the assent of the President. The President can return a bill to the Parliament, if it is not a money bill or a constitutional amendment bill, for reconsideration.
Description : A teenager has swelling involving his upper lip, the corner of his nose and a region under his left eye. The swollen area is soft, fluctuant and pointed on the labial plate under his ... and test vitality of his teeth E. Write prescription for antibiotics and delay treatment until swelling is
Last Answer : A. Refer him to physician IV abs riesgo de thrombosis de seno cavernoso
Description : Rotating the plane of polarization of a wavefront by passing it through a ferrite device is called what?
Last Answer : . Faraday rotation.
Description : What device is used to produce a gradual change in impedance at the end of a waveguide?
Last Answer : Horn.