Which of these is the best description of a zener diode?
It is a rectifier diode.
It is a constant-voltage device.
It is a constant-current device.
It works in the forward region.
A transistor has how many pn junctions?
1
2
3
4
The current gain of a transistor is defined as the ratio of the collector current to the
Base current
Emitter current
Supply current
Collector current
A zener diode
Is a battery
Has a constant voltage in the breakdown region
Has a barrier potential of 1 V
Is forward biased
The barrier potential across each silicon deletion layer is
0
0.3 V
0.7 V
1 V
When the base resistor increases, the collector voltage will probably
Decrease
Stay the same
Increase
Do all of the above
If the zener diode in a zener regulator is connected with the wrong polarity, the load voltage will be closest to
10 V
14 V
18 V
The emitter diode is usually
Forward biased
Reverse biased
Nonconducting
Operating in the breakdown region
If the base resistor is very small, the transistor will operate in the
Cutoff region
Active region
Saturation region
Breakdown region
At high frequencies, ordinary diodes don't work properly because of
Forward bias
Reverse bias
Breakdown
Charge storage
For normal operation of the transistor, the collector diode has to be
Reversed biased
Ignoring the bulk resistance of the collector diode, the collector-emitter saturation voltage is
A few tenths of a volt
Supply voltage
Breakdown does not destroy a zener diode, provided the zener current is less than the
Breakdown voltage
Zener test current
Maximum zener current rating
Barrier potential
Most of the electrons in the base of an npn transistor flow
Out of the base lead
Into the collector
Into the emitter
Into the base supply
If the base supply voltage is disconnected, the collector-emitter voltage will equal
0 V
6 V
10.5 V
Collector supply voltage
A photodiode is normally
Neither forward nor reverse biased
Emitting light
The base-emitter voltage is usually
Less than the base supply voltage
Equal to the base supply voltage
More than the base supply voltage
Cannot answer
The base current is 50 μA. If the current gain is 100, the collector current is closest in value to
50 μA
500 μA
2 mA
5 mA
The device associated with voltage controlled capacitance is a
Light-emitting diode
Photodiode
Varactor diode
Zener diode
The beta of a transistor is the ratio of the
Collector current to the emitter current
Collector current to base current
Base current to collector current
Emitter current to collector current
A circuit with a fixed emitter current is called
Base bias
Emitter bias
Transistor bias
Two-supply bias
To isolate an output circuit from an input circuit, which is the device to use?
Back diode
Optocoupler
Seven-segment indicator
Tunnel diode
The collector-emitter voltage is usually
Less than the collector supply voltage
Equal to the collector supply voltage
More than the collector supply voltage
When the current gain increases from 50 to 300 in an emitter-biased circuit, the collector current
Remains almost the same
Decreases by a factor of 6
Increases by a factor of 6
Is zero
If the base resistor is open, what is the collector current?
1 mA
10 mA
