What is the minimum allowable discharge voltage for maximum life of a standard 12-volt lead-acid battery?
Answer10.5 volts
For maximum service life, a standard 12-volt lead-acid battery should not normally be discharged below about 10.5 volts.
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G6 · Circuit Components
General · correct answers only, in question-pool order.
What is an advantage of batteries with low internal resistance?
AnswerHigh discharge current
Low internal resistance allows a battery to deliver a large current without excessive internal voltage drop or heating.
What is the approximate forward threshold voltage of a germanium diode?
Answer0.3 volts
A germanium diode begins conducting forward current at a much lower voltage than a silicon diode, typically around 0.3 volt.
Which of the following is characteristic of an electrolytic capacitor?
AnswerHigh capacitance for a given volume
Electrolytic capacitors provide relatively large capacitance in a compact package, which is why they are common in power-supply filtering.
What is the approximate forward threshold voltage of a silicon junction diode?
Answer0.7 volts
A silicon junction diode typically begins substantial forward conduction at about 0.7 volt.
Why should wire-wound resistors not be used in RF circuits?
AnswerThe resistor’s inductance could make circuit performance unpredictable
Wire-wound resistors behave partly like inductors because they are made from coiled resistance wire. At RF, that inductance can make circuit behavior unpredictable.
What are the operating points for a bipolar transistor used as a switch?
AnswerSaturation and cutoff
A bipolar transistor used as a switch is driven between cutoff for OFF and saturation for ON.
Which of the following is characteristic of low voltage ceramic capacitors?
AnswerComparatively low cost
Low-voltage ceramic capacitors are widely used in part because they are comparatively inexpensive.
Which of the following describes MOSFET construction?
AnswerThe gate is separated from the channel by a thin insulating layer
A MOSFET has an insulated gate: a thin insulating layer separates the gate electrode from the semiconductor channel.
Which element of a vacuum tube regulates the flow of electrons between cathode and plate?
AnswerControl grid
In a vacuum tube, the control grid varies the electron flow from cathode to plate and therefore controls tube current.
What happens when an inductor is operated above its self-resonant frequency?
AnswerIt becomes capacitive
Above its self-resonant frequency, an inductor's stray capacitance dominates and the component behaves capacitively rather than inductively.
What is the primary purpose of a screen grid in a vacuum tube?
AnswerTo reduce grid-to-plate capacitance
A screen grid reduces the capacitance between a vacuum tube's control grid and plate, helping isolate input from output.
What determines the performance of a ferrite core at different frequencies?
AnswerThe composition, or “mix,” of materials used
Ferrite behavior changes with material composition. Different ferrite mixes are formulated for different frequency ranges and applications.
What is meant by the term MMIC?
AnswerMonolithic Microwave Integrated Circuit
MMIC stands for Monolithic Microwave Integrated Circuit.
Which of the following is an advantage of CMOS integrated circuits compared to TTL integrated circuits?
AnswerLow power consumption
CMOS logic generally consumes far less static power than TTL logic, making low power consumption one of its major advantages.
What is a typical upper frequency limit for low SWR operation of 50-ohm BNC connectors?
Answer4 GHz
A 50-ohm BNC connector typically maintains low SWR through frequencies of roughly 4 GHz.
What inductance advantage can a ferrite-core toroidal inductor provide?
AnswerLarge values of inductance may be obtained.
The official G6B05 source identifies large obtainable inductance as one advantage of a ferrite-core toroidal inductor.
What frequency-range advantage can a ferrite-core toroidal inductor provide?
AnswerThe magnetic properties of the core may be optimized for a specific range of frequencies.
The official G6B05 source identifies frequency-specific core optimization as an advantage of ferrite toroidal inductors.
What magnetic-field advantage can a ferrite-core toroidal inductor provide?
AnswerMost of the magnetic field is contained in the core.
The official G6B05 source identifies confinement of most of the magnetic field within the core as an advantage of the toroidal form.
What kind of device is an integrated circuit operational amplifier?
AnswerAnalog
An integrated-circuit operational amplifier is an analog device used to amplify or process continuously varying voltages and currents.
Which of the following describes a type N connector?
AnswerA moisture-resistant RF connector useful to 10 GHz
A Type N connector is a threaded, moisture-resistant RF connector designed to perform well into the microwave region, with the pool citing usefulness to 10 GHz.
How is an LED biased when emitting light?
AnswerForward biased
An LED emits light when it is forward biased and current flows through its semiconductor junction.
How does a ferrite bead or core reduce common-mode RF current on the shield of a coaxial cable?
AnswerBy creating an impedance in the current’s path
A ferrite bead or core suppresses common-mode current by adding impedance to that unwanted current path.
What is an SMA connector?
AnswerA small threaded connector suitable for signals up to several GHz
An SMA connector is a small threaded RF connector widely used at UHF and microwave frequencies, including signals up to several GHz.
Which of these connector types is commonly used for low frequency or dc signal connections to a transceiver?
AnswerRCA Phono
RCA phono connectors are commonly used for low-frequency or DC signal connections rather than as high-performance RF connectors.