E5H Replacement of voltage source and
resistive voltage divider with
equivalent voltage source and one resistor (Thevenin's Theorem).
E5H01
(B)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 8 volts, R1 is 8 kilohms, and R2 is 8 kilohms?
A. R3 = 4 kilohms and V2 = 8 volts
B. R3 = 4 kilohms and V2 = 4
volts
C. R3 = 16 kilohms and V2 = 8 volts
D. R3 = 16 kilohms and V2 = 4 volts
E5H02
(C)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 8 volts, R1 is 16 kilohms, and R2 is 8 kilohms?
A. R3 = 24 kilohms and V2 = 5.33 volts
B. R3 = 5.33 kilohms and V2 = 8 volts
C. R3 = 5.33 kilohms and V2
= 2.67 volts
D. R3 = 24 kilohms and V2 = 8 volts
E5H03
(A)
In Figure
A5-1, what values of V2 and R3 result in the same voltage and current as when
V1 is 8 volts, R1 is 8 kilohms, and R2 is 16 kilohms?
A. R3 = 5.33 kilohms and V2
= 5.33 volts
B. R3 = 8 kilohms and V2 = 4 volts
C. R3 = 24 kilohms and V2 = 8 volts
D. R3 = 5.33 kilohms and V2 = 8 volts
E5H04
(D)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 10 volts, R1 is 10 kilohms, and R2 is 10 kilohms?
A. R3 = 10 kilohms and V2 = 5 volts
B. R3 = 20 kilohms and V2 = 5 volts
C. R3 = 20 kilohms and V2 = 10 volts
D. R3 = 5 kilohms and V2 = 5
volts
E5H05
(C)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 10 volts, R1 is 20 kilohms, and R2 is 10 kilohms?
A. R3 = 30 kilohms and V2 = 10 volts
B. R3 = 6.67 kilohms and V2 = 10 volts
C. R3 = 6.67 kilohms and V2
= 3.33 volts
D. R3 = 30 kilohms and V2 = 3.33 volts
E5H06
(A)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 10 volts, R1 is 10 kilohms, and R2 is 20 kilohms?
A. R3 = 6.67 kilohms and V2
= 6.67 volts
B. R3 = 6.67 kilohms and V2 = 10 volts
C. R3 = 30 kilohms and V2 = 6.67 volts
D. R3 = 30 kilohms and V2 = 10 volts
E5H07
(B)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 12 volts, R1 is 10 kilohms, and R2 is 10 kilohms?
A. R3 = 20 kilohms and V2 = 12 volts
B. R3 = 5 kilohms and V2 = 6
volts
C. R3 = 5 kilohms and V2 = 12 volts
D. R3 = 30 kilohms and V2 = 6 volts
E5H08 (B)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 12 volts, R1 is 20 kilohms, and R2 is 10 kilohms?
A. R3 = 30 kilohms and V2 = 4 volts
B. R3 = 6.67 kilohms and V2
= 4 volts
C. R3 = 30 kilohms and V2 = 12 volts
D. R3 = 6.67 kilohms and V2 = 12 volts
E5H09
(C)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 12 volts, R1 is 10 kilohms, and R2 is 20 kilohms?
A. R3 = 6.67 kilohms and V2 = 12 volts
B. R3 = 30 kilohms and V2 = 12 volts
C. R3 = 6.67 kilohms and V2
= 8 volts
D. R3 = 30 kilohms and V2 = 8 volts
E5H10
(A)
In
Figure A5-1, what values of V2 and R3 result in the same voltage and current as
when V1 is 12 volts, R1 is 20 kilohms, and R2 is 20 kilohms?
A. R3 = 10 kilohms and V2 =
6 volts
B. R3 = 40 kilohms and V2 = 6 volts
C. R3 = 40 kilohms and V2 = 12 volts
D. R3 = 10 kilohms and V2 = 12 volts
E5H11
(D)
What
circuit principle describes the replacement of any complex two- terminal
network of voltage sources and resistances with a single voltage source and a
single resistor?
A. Ohm's Law
B. Kirchhoff's Law
C. Laplace's Theorem
D. Thevenin's Theorem
E5I Photoconductive principles and
effects
E5I01
(B)
What is
photoconductivity?
A. The
conversion of photon energy to electromotive energy
B. The increased conductivity of an illuminated semiconductor
junction
C. The
conversion of electromotive energy to photon energy
D. The
decreased conductivity of an illuminated semiconductor junction
E5I02
(A)
What
happens to the conductivity of a photoconductive material when light shines on
it?
A. It increases
B. It
decreases
C. It
stays the same
D. It
becomes temperature dependent
E5I03
(D)
What
happens to the resistance of a photoconductive material when light shines on
it?
A. It
increases
B. It
becomes temperature dependent
C. It
stays the same
D. It decreases
E5I04
(C)
What
happens to the conductivity of a semiconductor junction when light shines on
it?
A. It
stays the same
B. It
becomes temperature dependent
C. It increases
D. It
decreases
E5I05
(D)
What is
an optocoupler?
A. A
resistor and a capacitor
B. A
frequency modulated helium-neon laser
C. An
amplitude modulated helium-neon laser
D. An LED and a phototransistor
E5I06
(A)
What is
an optoisolator?
A. An LED and a phototransistor
B. A
P-N junction that develops an excess positive charge when exposed to light
C. An
LED and a capacitor
D. An
LED and a solar cell
E5I07
(B)
What is
an optical shaft encoder?
A. An
array of neon or LED indicators whose light transmission path is controlled by
a rotating wheel
B. An array of optocouplers whose light transmission path is
controlled by a rotating wheel
C. An
array of neon or LED indicators mounted on a rotating wheel in a coded pattern
D. An
array of optocouplers mounted on a rotating wheel in a coded pattern
E5I08
(D)
What
characteristic of a crystalline solid will photoconductivity change?
A. The
capacitance
B. The
inductance
C. The
specific gravity
D. The resistance
E5I09
(C)
Which
material will exhibit the greatest photoconductive effect when visible light
shines on it?
A.
Potassium nitrate
B. Lead
sulfide
C. Cadmium sulfide
D.
Sodium chloride
E5I10
(B)
Which
material will exhibit the greatest photoconductive effect when infrared light
shines on it?
A.
Potassium nitrate
B. Lead sulfide
C.
Cadmium sulfide
D.
Sodium chloride
E5I11
(A)
Which
material is affected the most by photoconductivity?
A. A crystalline semiconductor
B. An
ordinary metal
C. A
heavy metal
D. A
liquid semiconductor
E5I12
(B)
What
characteristic of optoisolators is often used in power supplies?
A. They
have a low impedance between the light source and the phototransistor
B. They have a very high impedance between the light source and the
phototransistor
C. They
have a low impedance between the light source and the LED
D. They
have a very high impedance between the light source and the LED
E5I13
(C)
What
characteristic of optoisolators makes them suitable for use with a triac to
form the solid-state equivalent of a mechanical relay for a 120 V AC household
circuit?
A.
Optoisolators provide a low impedance link between a control circuit and a
power circuit
B.
Optoisolators provide impedance matching between the control circuit and power
circuit
C. Optoisolators provide a very high degree of electrical isolation
between a control circuit and a power circuit
D.
Optoisolators eliminate (isolate) the effects of reflected light in the control
circuit