E6D Vidicon and cathode-ray tube
devices; charge-coupled devices
(CCDs); liquid crystal displays (LCDs); toroids: permeability, core
material, selecting, winding
E6D01
(D)
How is
the electron beam deflected in a vidicon?
A. By varying the beam voltage
B. By varying the bias voltage on the beam
forming grids inside the tube
C. By varying the beam current
D. By varying
electromagnetic fields
E6D02
(D)
What is
cathode ray tube (CRT) persistence?
A. The time it takes for an image to appear after
the electron beam is turned on
B. The relative brightness of the display under
varying conditions of ambient light
C. The ability of the display to remain in
focus under varying conditions
D. The length of time the
image remains on the screen after the beam is turned off
E6D03
(A)
If a
cathode ray tube (CRT) is designed to operate with an anode voltage of 25,000
volts, what will happen if the anode voltage is increased to 35,000 volts?
A. The image size will
decrease and the tube will produce X-rays
B. The image size will increase and the tube
will produce X-rays
C. The image will become larger and brighter
D. There will be no apparent change
E6D04
(B)
Exceeding
what design rating can cause a cathode ray tube (CRT) to generate X-rays?
A. The heater voltage
B. The anode voltage
C. The operating temperature
D. The operating frequency
E6D05
(C)
Which
of the following is true of a charge-coupled device (CCD)?
A. Its phase shift changes rapidly with
frequency
B. It is a CMOS analog-to-digital converter
C. It samples an analog
signal and passes it in stages from the input to the output
D. It is used in a battery charger circuit
E6D06
(A)
What
function does a charge-coupled device (CCD) serve in a modern video camera?
A. It stores photogenerated
charges as signals corresponding to pixels
B. It generates the horizontal pulses needed
for electron beam scanning
C. It focuses the light used to produce a
pattern of electrical charges corresponding to the image
D. It combines audio and video information to
produce a composite RF signal
E6D07
(B)
What is
a liquid-crystal display (LCD)?
A. A modern replacement for a quartz crystal
oscillator which displays its fundamental frequency
B. A display that uses a
crystalline liquid to change the way light is refracted
C. A frequency-determining unit for a
transmitter or receiver
D. A display that uses a glowing liquid to
remain brightly lit in dim light
E6D08
(D)
What
material property determines the inductance of a toroidal inductor with a 10-turn
winding?
A. Core load current
B. Core resistance
C. Core reactivity
D. Core permeability
E6D09
(B)
By
careful selection of core material, over what frequency range can toroidal
cores produce useful inductors?
A. From a few kHz to no more than several MHz
B. From DC to at least 1000
MHz
C. From DC to no more than 3000 kHz
D. From a few hundred MHz to at least 1000 GHz
E6D10
(A)
What
materials are used to make ferromagnetic inductors and transformers?
A. Ferrite and powdered-iron
toroids
B. Silicon-ferrite toroids and shellac
C. Powdered-ferrite and silicon toroids
D. Ferrite and silicon-epoxy toroids
E6D11
(B)
What is
one important reason for using powdered-iron toroids rather than ferrite
toroids in an inductor?
A. Powdered-iron toroids generally have greater
initial permeabilities
B. Powdered-iron toroids
generally have better temperature stability
C. Powdered-iron toroids generally require
fewer turns to produce a given inductance value
D. Powdered-iron toroids are easier to use with
surface-mount technology
E6D12
(B)
What
would be a good choice of toroid core material to make a common-mode choke
(such as winding telephone wires or stereo speaker leads on a core) to cure an
HF RFI problem?
A. Type 61 mix ferrite (initial permeability of
125)
B. Type 43 mix ferrite
(initial permeability of 850)
C. Type 6 mix powdered iron (initial
permeability of 8)
D. Type 12 mix powdered iron (initial
permeability of 3)
E6D13
(C)
What
devices are commonly used as parasitic suppressors at the input and output
terminals of VHF and UHF amplifiers?
A. Electrolytic capacitors
B. Butterworth filters
C. Ferrite beads
D. Steel-core toroids
E6D14
(A)
What is
a primary advantage of using a toroidal core instead of a linear core in an
inductor?
A. Toroidal cores contain
most of the magnetic field within the core material
B. Toroidal cores make it easier to couple the
magnetic energy into other components
C. Toroidal cores exhibit greater hysteresis
D. Toroidal cores have lower Q characteristics
E6D15
(C)
How
many turns will be required to produce a 1-mH inductor using a ferrite toroidal
core that has an inductance index (A sub L) value of 523?
A. 2 turns
B. 4 turns
C. 43 turns
D. 229 turns
E6D16
(A)
How
many turns will be required to produce a 5-microhenry inductor using a
powdered-iron toroidal core that has an inductance index (A sub L) value of 40?
A. 35 turns
B. 13 turns
C. 79 turns
D. 141 turns