ELECTRICITY AND ELECTRONICS TRAINING SERIES. MODULE 7-SOLID-STATE DEVICES AND POWER SUPPLIES
Approximately how many times is the mass of the proton to that of an electron?
1,827
Who invented the photophone?
Alexander Graham Bell
What is often used when it is necessary to block the voltage between one electronic circuit and another, and transfer the signal at the same time?
Amplifier coupling capacitor
What gives an indication of how much the output voltage changes over a range of load resistance values?
Figure of merit
Which band are electrons never found in, but may travel back and forth through it, provided they do not come to rest in the band
Forbidden
How many basic types of filter circuits are there?
Four
Which type of device has two or more diodes arranged so that load current flows in the same direction during each half cycle of the ac supply?
Full-wave rectifier
Which type of material was found to be the most sensitive for use in early radio receivers?
Galena
What is the conversion of an alternating current to a pulsating direct current?
Rectification
What converts the alternating current input signal to a pulsating direct current?
Rectifier
Most power supplies are made up of the following four basic sections: transformer, rectifier, filter, and what else?
Regulator
What is the simplest type of rectifier circuit?
Half-wave rectifier
Basic voltage regulators are classified as one of what two ways?
Series or Shunt
Which material used in communications was found to be the most stable?
Silicon
Which type of device operates by virtue of the movement of electrons within a solid piece of semiconductor material?
Solid -state
What are the three states that matter may be found in?
Solids, liquids, and gases
What is a PN junction that is designed to operate in the reverse- bias breakdown region?
Zener diode
What is the overall charge of N material?
Zero
The MOSFET has a higher input impedance than the JFET (how many megohms)
10 to 100 million
Electrolytic capacitors are available in sizes up to how many microfarads or greater?
10,000
What is an external voltage applied to a PN junction called?
Bias
The input resistance of the SCR is relatively low (approximately how many ohms) and requires a current for triggering?
100
The maximum power output for transistor generally ranges from 30 milliwatts to slightly over how many watts?
100
What is the life expectancy of the LED?
100,000+ hours
In the tunnel diode, the semiconductor materials used in forming a junction are doped to the extent of how many impurity atoms for ten-million semiconductor atoms?
1000
115 volts AC can vary from about 105 volts AC to how many volts AC?
125
Which year did Michael Faraday discover that silver sulfide, a semiconductor, has a negative temperature coefficient?
1883
Which year did Munk A. Rosenshold find that certain materials have rectifying properties?
1885
Which year was the zener effect first proposed by Dr. Carl Zener?
1934
Which year did Leo Esaki discover that if a semiconductor junction diode is heavily doped with impurities then it will have a region of negative resistance?
1958
What is a typical light-to-dark resistance ratio for a photocell?
1:1000
What percent of a half -wave rectifier is the ripple frequency of a full- wave rectifier?
200%
Some SCRs can be switched how many times a second?
25,000
How many distinct types of UJTs are presently in use?
40+
The maximum allowable voltage for a transistor is limited to about 200 volts (but usually how many volts or less)?
50
What temperature is the maximum average forward current usually given at?
77 degrees F
What is the maximum reverse DC voltage that will not cause breakdown called?
DC Blocking voltage
The MOSFET is normally constructed so that it operates in one of what two basic modes?
Depletion or Enhancement
What are two terminal semiconductors of various types that are used in seemingly endless applications?
Diodes
What is the process by which small amounts of selected additives, called impurities, are added to semiconductors to increase their current flow?
Doping
Whose initial work led to the development of zener diode which is frequently used today to regulate power supply voltages at precise levels?
Dr. Carl Zener
What is the amount of energy required by an electron to stay in orbit?
Electron energy level
The chemical activity of an atom is determined by the number of what in its valence shell?
Electrons
Which substance cannot be reduced to a simpler form by chemical means?
Element
What uses voltage to control an electrostatic field within the transistor?
FET
Which type of devices either produce light or use light in their operation?
Optoelectronic
Which type of device is obtained when a section of N-type semiconductor material is joined with a similar section of P -type semiconductor material?
PN Junction
What offers very little resistance to current flow in the forward -bias direction but maximum resistance to current flow when reverse biased?
PN junction diode
What indicates the maximum reverse-bias voltage that may be applied to a diode without causing junction breakdown?
PRV
Arsenic, antimony, bismuth, and phosphorous are all what type of impurities?
Pentavalent
What is a list of all the known elements with the number of electrons in each atom contained?
Periodic table of elements
What is a light-controlled variable resistor?
Photodiode
Which type of device converts light energy into electrical energy?
Photovoltaic cell
What could be designed to work within the ultra-high frequencies used in radar, whereas the electron tube could not?
Point-contact semiconductor diode
What carries a positive charge of electricity equal and opposite to the charge of the electron?
Proton
What is current called that flows in pulses in the same direction?
Pulsating DC
In simple terms, energy is required in definite units to move electrons from one shell to the next higher shell. What are these units called?
Quanta
Which process according to Dr. Zener's theory does electrical breakdown in solid dielectrics occur by?
Quantum-Mechanical tunneling
Which terms are AC voltages normally specified in?
RMS values
What is one of the most important uses of a diode?
Rectification
What functions as a switch that can turn on or off small or large amounts of power?
SCR
Copper-oxide rectifiers are generally used in small-current applications such as AC meter movements or for delivering direct current to circuits requiring not more than how many amperes?
10
LED operating voltage is small, about 1.6 volts forward bias and generally about how many milliamperes?
10
How high can the ratio of varactor capacitance to reverse-bias voltage change be?
10 to 1
What is the smallest particle into which an element can be broken down and still retain all its original properties?
Atom
What is the electrostatic field called that is created by the positive and negative ions in the depletion region?
Barrier
What is the most basic type of power supply filter?
Capacitor filter
What provides two equal voltages to the conventional full-wave rectifier?
Center-tapped transformer
What is a chemical combination of two or more elements called?
Compound
What is a band in which the energy level of the electrons is high enough that the electrons will move easily under the influence of an external field?
Conduction
What is a material in which the forbidden gap is so narrow that it can be considered nonexistent?
Conductor
What are solid materials called that have many electrons in the conduction band?
Conductors
There are many known metal-semiconductor combinations that can be used for contact rectification. Which devices are by far the most popular?
Copper oxide and selenium
What is a solid whose atoms or molecules are arranged in a three- dimensional geometrical pattern commonly referred to as a lattice called?
Crystal
What are materials in which the forbidden gap is so large that practically no electrons can be given enough energy to cross the gap?
Insulators
What is a minute piece of semiconductor material that can produce complete electronic circuit functions?
Integrated circuit
In which process does an atom lose or gain electrons?
Ionization
What are two of the most widely known semiconductors that are in use today?
Junction diode and the Transistor
What is one of the most commonly used filters primarily used in radio receivers,small audio amplifier power supplies, and in any type of power supply where the output current is low and the load current is relatively constant?
LC capacitor-input filter
Which type of filter is primarily used in power supplies where voltage regulation is important and where the output current is relatively high and subject to varying load conditions?
LC choke-input
What is any device that draws current defined as?
Load
What is a solid that contains a forbidden gap
Semiconductor
What is anything that occupies space and has weight known as?
Matter
Which two parts is the universe, as we know it today, divided into?
Matter and energy
What is the maximum current called that is permitted to flow in the forward direction in the form of nonrecurring pulses?
Maximum surge current
What is the smallest part of a compound called which has all the characteristics of the compound?
Molecule
What is the most important and most widely used characteristic of the tunnel diode?
Negative resistance region
What has a mass approximately equal to that of a proton but has no electrical charge?
Neutron
What can be used to check a varactor diode in a circuit
Ohmmeter
What is the most convenient and quickest way of testing a diode?
Ohmmeter
What is defined as the time it takes a capacitor to charge to 63.2 percent of the applied voltage or to discharge to 36.8 percent of its total charge?
One time constant
Transistors are semiconductor devices with how many or more terminals?
Three
What steps up or steps down the input line voltage and isolates the power supply from the power line?
Transformer
Aluminum, indium, gallium, and boron are all what type of impurities?
Trivalent
The conduction band along with which other band are the two energy bands that an electron can exist in?
Valence
What is a band in which the energy level is the same as the valence electrons of the atoms?
Valence
What is an atom's ability to combine with other atoms called?
Valence
What is the outer shell of an atom called?
Valence shell
Which type of diode behaves like a variable capacitor, with the PN junction functioning like the dielectric and plates of a common capacitor?
Varactor
What is the most widespread use of Zener diodes?
Voltage regulators
