semiconductor diodes Flashcards
Which of the following devices can check the condition of a semiconductor diode?
A) Digital display meter (DDM)
B) Multimeter
C) Curve tracer
D) All of the above
D
How many orbiting electrons does the germanium atom have?
32
What is the range of the operating voltage level for LEDs?
1.7–3.3 V
The _________ diode model is employed most frequently in the analysis of electronic systems.
simplified
The forward characteristics curve of a diode grows in _______ form.
exponential
Diodes are connected _______ to increase the current-carrying capacity.
in parallel
A(n) _______ is the simplest of semiconductor devices.
diode
In the atomic lattice the _______ and _______ form the nucleus.
neutrons, protons
It is not uncommon for a germanium diode with an Is in the order of 1–2 A at 25°C to have leakage current of 0.1 mA at a temperature of 100°C. True or False.
True
How many valence electrons does a silicon atom have?
4
In which of the following is the light intensity measured?
Candela
Varying the _______ can control the location of the Zener region.
doping levels
The ac resistance of a diode is the _______ of the characteristic curve at the Q-point of operation.
reciprocal of the slope
The intensity of LED is greatest at _______ degrees and the least at _______ degrees.
0, 90
At what kind of operating frequency diffusion or transition is a capacitor represented in parallel with the ideal diode?
A) Low frequency
B) Moderate frequency
C) Mid frequency
D) Very high frequency
D) Very high frequency
The diode _______.
A) is the simplest of semiconductor devices
B) has characteristics that closely match those of a simple switch
C) is a two-terminal device
D) All of the above
D) All of the above
In n-type material the _______ is called the majority carrier.
electron
The diffused impurities with _______ valence electrons are called acceptor atoms.
3
What is the state of an ideal diode in the region of nonconduction?
An open circuit
The condition of a semiconductor diode can be determined quickly using a _________.
A) DDM
B) VOM
C) curve tracer
D) Any of the above
D) Any of the above
The test current in a Zener diode IZT is the current defined by the _______ power level.
0.25
Calculate the temperature coefficient in %/°C of a 10-V nominal Zener diode at 25°C if the nominal voltage is 10.2 V at 100°C.
0.0267
Which of the following ratings is true?
A) Si diodes have higher PIV and narrower temperature ranges than Ge diodes.
B) Si diodes have higher PIV and wider temperature ranges than Ge diodes.
C) Si diodes have lower PIV and narrower temperature ranges than Ge diodes.
D) Si diodes have lower PIV and wider temperature ranges than Ge diodes.
B) Si diodes have higher PIV and wider temperature ranges than Ge diodes.
What does a high resistance reading in both forward- and reverse-bias directions indicate?
A) A good diode
B) An open diode
C) A shorted diode
D) A defective ohmmeter
B) An open diode
One eV is equal to _______ J.
1.6 × 10^–19
Which of the following elements is most frequently used for doping pure Ge or Si?
A) Boron
B) Gallium
C) Indium
D) All of the above
D) All of the above
What is the maximum power rating for LEDs?
150 mW
Calculate the power dissipation of a diode having ID = 40 mA.
28 mW
Which capacitance dominates in the reverse-bias region?
A) depletion
B) conversion
C) Diffusion
D) None of the above
A) depletion
Any electron that has left its parent atom has _______ energy state relative to any electron in the atomic structure.
A) the same
B) a lower
C) a higher
D) an undefined
C) a higher
The diffused impurities with ________ valence electrons are called donor atoms.
5
The potential at which the characteristics curve vertical rise occurs is commonly referred to as the _______.
A) offset
B) threshold
C) firing potential
D) All of the above
D) All of the above
Which capacitance dominates in the forward-bias region?
A) Diffusion
B) Transition
C) Depletion
D) None of the above
A) Diffusion
Determining rd to a high degree of accuracy from a characteristic curve is very accurate.
A) True
B) False
B) False
Calculate static resistance RD of a diode having ID = 30 mA and VD = 0.75 V.
25
Generally the value of ac resistance is _______ the value of dc resistance at the same operating point.
A) smaller than
B) larger than
C) the same as
D) unrelated to
A) smaller than
The reverse-saturation current level is typically measured in _______.
A) pA
B) µA
C) mA
D) A
B) µA
The heavier the current in a Zener diode in reverse bias, _______ dynamic resistance value.
A) the more the
B) the less the
C) there is substantially more
D) there is no change in the
B) the less the
The reverse-bias current _______ with the increase of temperature.
A) decreases
B) increases
C) remains the same
D) None of the above
B) increases
The temperature coefficient can be _______ for different Zener levels.
A) positive
B) negative
C) zero
D) All of the above
D) All of the above
The term ________ is often used when comparing the resistance level of materials.
resistivity
How many terminals does a diode have?
2
In general, LEDs operate at voltage levels from _____ V to _____ V.
1.7, 3.3
What is the value of the transition capacitance for a silicon diode when VD = 0?
3 pF
The _______ the current through a diode, the _______ the dc resistance level.
A) higher, lower
B) lower, lower
C) lower, higher
D) higher, higher
C) lower, higher
The reverse saturation current Is will just _______ in magnitude for every 10° C increase in temperature.
A) double
B) remain the same
C) halve
D) triple
A) double
Determine the nominal voltage for the Zener diode at a temperature of 120°C if the nominal voltage is 5.1 volts at 25°C and the temperature coefficient is 0.05%/°C.
5.34 V
The ideal diode is a(n) _______ circuit in the region of nonconduction.
A) open
B) short
A) open
In which of the following color(s) is (are) LEDs presently available?
A) Yellow
B) White
C) Orange
D) All of the above
D) All of the above
Calculate ID if RD = 30 and VD = 0.84 V.
28 mA
