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 : When you are testing the gain of an audio-frequency transistor with an ohmmeter, what is indicated by a 10-to-1 resistance ratio?
Last Answer : Normal gain.
Description : What are two transistor tests that can be done with an ohmmeter?
Last Answer : Gain and junction resistance.
Description : When troubleshooting a console circuit card suspected of being faulty, first check operating voltages, clean the card and then _________________. A. make sure wired connections and push-on connectors ... circuit traces with an ohmmeter D. measure the gain of each transistor or integrated circuit
Last Answer : Answer: A
Description : To conduct an in-circuit test of a transistor, you should use a/an ____________. A. voltmeter or transistor tester B. impedance meter C. ohmmeter or transistor tester D. wattmeter
Description : In order to check the performance of a transistor removed from its circuit, the instrument to be used should be a/an ____________. A. voltmeter or transistor tester B. impedance meter C. ohmmeter or transistor tester D. sensitive potentiometer
Last Answer : Answer: C
Description : The development of excessive test voltages is avoided by the use of meggers equipped with what device?
Last Answer : Friction clutches.
Last Answer : Friction clutches
Description : Describe thermal runaway of transistor and explain how it can be avoided.
Last Answer : Concept of thermal runaway: 1.We know that IC = β IB + (1+ β) ICO Where ICO is the leakage current and ICO is strongly dependent on temperature. 2. Leakage current approximately doubles for ... Thermal runaway can be avoided by : 1) Using stabilization circuitry 2) Heat sink
Description : Which of the listed statements is correct when using an analog multimeter as an ohmmeter? A. The pointer should be adjusted to zero each time a new resistance range is selected. B. The ... C. Ohmmeters are not sufficiently sized to measure conductor insulation resistance. D. All of the above.
Last Answer : Answer: D
Description : What must be done to a circuit before you can use an ohmmeter for testing?
Last Answer : It must be de-energized.
Description : When checking a diode with an ohmmeter, what is indicated by two high resistance measurements?
Last Answer : The diode is open or has a high-forward resistance.
Description : When testing an SCR with an ohmmeter, the SCR will conduct if what two elements are shorted together?
Last Answer : Gate and anode.
Description : Before you connect a VOM in a circuit for an ohmmeter reading, in what condition must the circuit be?
Last Answer : De-energized
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 : 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 area of an ohmmeter scale should be used when measuring circuits?
Last Answer : The middle of the scale.
Description : What is used to provide the ohmmeter with several ranges?
Last Answer : An ohmmeter has several internal range resistors and a switch or a series of jacks to select the proper range.
Description : How is a series-type ohmmeter connected to the circuit being measured?
Last Answer : The ohmmeter is connected in series with the resistance to be measured.
Description : What other measurement can an ohmmeter make?
Last Answer : Circuit continuity.
Description : What electrical quantity is measured by an ohmmeter?
Last Answer : Resistance.
Description : The R x 100 resistance selection on an ohmmeter has what amount of resistance compared to the R x 10 selection?
Last Answer : 1/10.
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 : 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
Description : When using an ohmmeter to test a semiconductor diode, you find a low resistance in both the forward and reverse bias directions. This indicates that the diode has a/an ____________. A. open B. short C. good resistive quality D. good capacitive quality
Last Answer : Answer: B
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 : Prior to using an analog type ohmmeter, the leads are purposely shorted together. Which of the following actions should be taken if, when adjusting to 'zero' ohms, the indicating needle can not be ... be added to each final reading. D. The test reading should be subtracted from each final reading.
Description : You are performing an out-of-circuit test of the semi-conductor shown in the illustration. Using an ohmmeter on 'low power' position and with leads properly installed, which of the listed results would you expect the ... lead on 'B' and black lead on 'A'; and a low reading with the leads reversed.
Description : You are performing an out-of-circuit test of the semi-conductor shown in the illustration. Using an ohmmeter on 'low power' position and with leads properly installed, which of the listed results would indicate a good ... lead on 'A' and red lead on 'C'; and a high reading with the leads reversed.
Description : You are performing an out-of-circuit test on the semi-conductor shown in the illustration. Using an ohmmeter on 'low power' setting and with leads properly inserted, which of the listed results would indicate a good ... lead on 'A' and red lead on 'C'; and a high reading with the leads reversed.
Description : While testing a semi-conductor diode with an ohmmeter, both the forward and reverse readings are almost in the infinity range. This would indicate that the unit is _____________. A. good B. open C. grounded D. shorted
Description : Device to control the pressure of fluid and gases within range of settings. a. Relief valve. c. Filter b. Spray gun. d. Pressure regulator
Last Answer : Pressure regulator
Description : In a sawtooth generator, why is the transistor turned on for a longer time than the discharge time of the RC network?
Last Answer : To allow the capacitor time to discharge.
Description : What are the factors that limit the frequency response of a transistor amplifier?
Last Answer : The capacitance and inductance of the circuit and the interelectrode capacitance of the transistor.
Description : How is the collector lead identified on an oval-shaped transistor?
Last Answer : By the wide space between the collector lead and the other two leads (emitter and base)
Description : What safety precaution must be taken before replacing a transistor?
Last Answer : The power must be removed from the circuit.
Description : Which transistor configuration has the highest input resistance?
Last Answer : Common collector.
Description : Which transistor configuration has a current gain of less than 1?
Last Answer : Common base.
Description : What method for checking transistors is cumbersome when more than one transistor is bad in a circuit?
Last Answer : The substitution method.
Description : What is the greatest danger to a transistor?
Last Answer : Heat.
Description : List three items of information normally included in the general description section of a specification sheet for a transistor.
Last Answer : The kind of transistor, the transistor's common applications, and mechanical data
Description : In the basic transistor amplifier discussed earlier, what is the relationship between the polarity of the input and output signals?
Last Answer : The signals are opposite in polarity or 180 degrees out of phase with each other.
Description : Name the two current loops in a transistor.
Last Answer : The base current loop and the collector current loop
Description : What is the relationship between the polarity of the voltage applied to the PNP transistor and that applied to the NPN transistor?
Last Answer : The polarity of voltage applied to the PNP transistor is opposite of that applied to the NPN
Description : What are the majority current carriers in a PNP transistor?
Last Answer : Holes.
Description : What percentage of current in an NPN transistor reaches the collector?
Last Answer : 98 percent.
Description : In the NPN transistor, what section is made very thin compared with the other two sections?
Last Answer : The P or base section.