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 : To properly bias an NPN transistor, what polarity voltage is applied to the collector, and what is its relationship to the base voltage?
Last Answer : Positive, more positive.
Description : In a transistor, the conventional current flows from base to emitter. The transistor is (a) NPN (b) PNP (c) FET (d) None of these
Last Answer : (a) NPN
Description : When an NPN transistor is properly biased then most of the electrons from the emitter (A) recombine with holes in the base (B) recombine in the emitter itself (C) pass through the base to the collector (D) are stopped by the junction barrier
Last Answer : a
Description : What is the result of pulsing a pulsed rf amplifier when no rf is present?
Last Answer : Oscillations at an undesired frequency.
Description : What is average power in a pulsed system?
Last Answer : Peak power during a pulse averaged over pulse time plus rest time.
Description : What is the input current in the common-emitter circuit?
Last Answer : Base current (IB).
Description : What is the primary difference between the NPN and PNP amplifiers?
Last Answer : The polarity of the source voltage
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.
Description : In which direction does the arrow point on an NPN transistor?
Last Answer : Outward.
Description : When used for ac current control, during which alternation of the ac cycle does the TRIAC control current flow?
Last Answer : During both alternations.
Description : Does a rectifier tube conduct on the positive or negative alternation of the input signal?
Last Answer : Positive.
Description : In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit (1) All calculations done earlier have to be repeated (2) Replace all calculated voltages by ... all calculated currents by reverse values (4) Replace all calculated voltages and currents by reverse values
Last Answer : In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit Replace all calculated voltages and currents by reverse values
Description : Besides eliminating the emitter-base battery, what other advantages can different biasing methods offer?
Last Answer : Compensation for slight variations in transistor characteristics and changes in transistor conduction because of temperature variations.
Description : the voltage drop across RS and R1 determines the amount of base-emitter ____ for Q1.
Last Answer : Bias.
Description : How is the output signal developed in the common-emitter detector?
Last Answer : By the collector current flow through R4.
Description : Which junction of the transistor in the common-emitter detector detects the modulation envelope?
Last Answer : Emitter-base junction
Description : What causes the change in collector current in an emitter injection modulator?
Last Answer : Gain is varied by changing the voltage on the emitter.
Description : A negative damper with negative bias clamps the most positive extremity of the output wave shape to what polarity (positive or negative)?
Last Answer : Negative potential.
Description : To which polarity does a positive damper with positive bins clamp the most negative extremity of the output waveform (positive or negative)?
Last Answer : Positive potential.
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 : Using Weber’s molecular theory of magnetism, describe the polarity of the magnetic poles produced by stroking a magnetic material from right to left with the south pole of a magnet.
Last Answer : South pole at the right, north pole at the left.
Description : Before a diode will conduct, the cathode must be what polarity relative
Last Answer : Negative.
Description : If logic 1 = -5 vdc and logic 0 = 0 vdc, what logic polarity is being used?
Description : If logic 1 = +2 vdc and logic 0 = -2 vdc, what logic polarity is being used?
Description : If logic 1 = -5 vdc and logic 0 = -10 vdc, what logic polarity is being used?
Description : In applying Kirchhoff’s current law, what does the polarity of the current indicate?
Last Answer : Whether the current is entering the junction (+) or leaving the junction (-).
Description : What is the polarity of the currents that feed the V antenna?
Last Answer : Opposite.
Description : What is the term for the number of times per second that tank circuit energy is either stored in the inductor or capacitor?
Last Answer : Natural frequency or resonant frequency (f r).
Description : When the magnetic field of the inductor is completely collapsed, where is the energy of the tank circuit stored?
Last Answer : . Capacitor.
Description : When the capacitor is completely discharged, where is the energy of the tank circuit stored?
Last Answer : Inductor magnetic field
Description : What type of impedance does the tank circuit have above resonance?
Last Answer : Inductive.
Description : What type of tank circuit is used in the Foster-Seeley discriminator?
Last Answer : A double-tuned tank circuit.
Description : What component in a blocking oscillator controls pulse width?
Last Answer : Transformer.
Description : What signal is used to synchronize the coherent oscillator to a fixed phase relationship with the transmitted pulse?
Last Answer : Coho lock pulse.
Description : What is the primary advantage of power-amplifier transmitters over keyed-oscillator transmitters?
Last Answer : Frequency stability.
Description : Name a disadvantage of sine-wave oscillator synchronizers.
Last Answer : It requires additional shaping circuits.
Description : What basic circuits meet the requirements of an externally synchronized master oscillator?
Last Answer : Sine-wave oscillator, single-swing blocking oscillator, and master trigger (astable) multivibrator.
Last Answer : . It requires additional shaping circuits.
Description : What type of multivibrator can be used as a radar master oscillator?
Last Answer : Free-running.
Description : What transmission method uses a stable cw reference oscillator, which is locked in phase with the transmitter frequency?
Last Answer : Pulse-Doppler.
Description : When a transmitter uses a high-power oscillator to produce the output pulse, what switches the oscillator on and off?
Last Answer : High-voltage pulse from the modulator.
Description : Why is a high-gain transistor used in the phase-shift oscillator?
Last Answer : Because of the losses encountered in the RC networks.
Description : Which components provide the regenerative feedback signal in the phase-shift oscillator?
Last Answer : Resistor-capacitor networks.
Description : What is the identifying feature of a Colpitts oscillator?
Last Answer : Split capacitors.
Description : What is the difference between the series-fed and the shunt-fed Hartley oscillator?
Last Answer : In the series-fed Hartley oscillator, dc flows through the tank circuit.