M4 B2 Flashcards
(43 cards)
What is done to an element to make it a semiconductor material?
The lattice of pure element is doped with elements that contain 3 or 5 valence electrons.
What is most commonly used as rectifiers in electrical circuits?
Diodes
When a PN junction is forward biased, the depletion zone …
narrows
The voltage applied to a reversed biased diode that causes the diode to breakdown and allow current flow is known as …
Avalanche Voltage
A typical application for Zener diodes is as …
Voltage regulators.
A rectifier Diode is used in applications that require … current
High
Name three dangers of diodes
Heat, over-voltage and over-current diodes.
A diode offers … to current flow which causes a … drop
- resistance
2.Voltage
A sillicon controlled Rectifier (SRC´s) use a … to control when current flow through the device
gate
UJT´s (unijunction) and FET´s(Field Effect) are types of …
Transistors
Complementary MOSFET(CMOS) devices are used to make … to build digital logic gates
transistors
What logic gate will provide an active high output only when all inputs are different?
Exclusive Or
The board of a printed circuit board is made of what material?
non-conductive
what is a conductive path on a printed circuit board is called
Trace
True or false
An open loop system uses feedback to ensure that controlled mechanisms have been moved to the proper position.
False. Closed loop systems have feedback, an open loop system does not.
Which describes the basic operation of a synchro system for
remote position indication?
1. A transmitter sends varying voltages to an indicator
motor which moves a pointer.
2. Resistances are compared in the transmitter and the
result is sent to the indicator motor to position a pointer.
3. A magnetic field in the transmitter is mirrored in the
indicator where a magnetic rotor aligns with the
magnetic field.
- A magnetic field in the transmitter is mirrored in the
indicator where a magnetic rotor aligns with the
magnetic field.
What three factors affect the amount of electricity that a capacitor can store?
Area of the plates, Distance of the plates and the Dielectric constant of the material between the plates.
The relationship between frequency and wavelength is …
inversely proportional
radio waves are directional and propagate out into space at …
186,282 miles per second (speed of light)
The electric field component and the … component of a radio wave are oriented 90° to each other, and at 90° to the direction that the wave is traveling
electromagnetic field
Ground waves or surface radio waves follow the curvature of the earth and are
low frequency waves
VHF communication radios are the primary communication radios used in aviation. They operate in what frequency range?
118.0 MHz to 136.975 MHz
To transmit and receive useful information, a radio wave is altered or modulated by …
an information signal
In an AM radio transmission, the radio wave is altered to carry useful information by modulating the …
Amplitude of the wave.
