Midterm 2

Which of the following circuits is part of a typical DC power supply? Select one: a.A high pass filter b.All of these c.A load resistor d.A diode rectifier e.A current regulator

A diode rectifier

In a semiconductor the number of holes multiplied by the number of electrons is equal to a constant except when dopant atoms are added.

False

In the small-signal equivalent for a circuit containing a reverse biased Zener diode, the DC battery is used to model the diode's reverse breakdown voltage at high current levels.

False

Intrinsic semiconductors have controlled amounts of impurity atoms added to vary their resistance.

False

Lightly doped PN junctions break down at lower reverse voltages than heavily doped PN junctions.

False

Line regulation is a measure of how much a reference voltage changes as the load current changes.

False

Linear circuit analysis techniques can be applied to nonlinear circuits as long as the variations around the bias point are kept large enough.

False

Load regulation is a measure of how much a reference voltage changes as the input supply voltage changes.

False

One of the most useful applications for diodes is in DC power supplies, which convert a DC input voltage into an AC output voltage.

False

Peak Detectors are often used to create an output voltage which is equal to the average value of an input signal.

False

The RC time constant for the filter capacitor in a power supply is typically set much smaller than the period of the input sine wave.

False

The RC time constant for the filter capacitor in a power supply is typically set so large that the capacitor discharge appears exponential.

False

The depletion region capacitance decreases linearly as the reverse bias voltage is increased.

False

The diffusion capacitance for a PN junction is directly proportional to temperature.

False

The diffusion capacitance for a PN junction is inversely proportional to the average time it takes for a carrier to recombine after it crosses the junction.

False

The drain current for a triode MOSFET increases linearly at first for small values of Vds, but then increases more slowly as Vds is increased further because the resistance of the channel near the source end goes up as Vds is increased.

False

The final stage in a power supply is a voltage regulator, which keeps the output voltage constant even if the output is shorted.

False

The minimum value for the depletion region capacitance of a reverse biased PN junction occurs when the reverse bias is equal to zero volts.

False

The peak current which flows in the rectifier diodes for a power supply is often much smaller than the current supplied to the load

False

The peak current which flows in the rectifier diodes for a power supply is often much smaller than the current supplied to the load.

False

The separation of charge caused by the immobile ions in the depletion region surrounding a PN junction causes the "built-in voltage", which assists the further diffusion of electrons and holes.

False

The size of the ripple voltage at the output of a power supply filter capacitor is directly proportional to the size of the filter capacitor used.

False

The slope of the Id versus Vds curve for a MOSFET in saturation is zero.

False

The small-signal model for a diode could be used to find both the voltage gain and the clipping levels of a circuit containing diodes, but it's much easier to find the voltage gain using the large-signal model.

False

The standard approximation of a 0.7V drop across a forward biased diode is actually too low when the current flowing through the diode is a few microamps.

False

The threshold voltage for an NMOS FET is negative.

False

The threshold voltage of a MOSFET is the amount of voltage that must be applied between the drain and source in order for a channel to be formed between the gate and source.

False

In a Half-wave rectifier without a filter capacitor, the minimum breakdown voltage required for the diodes is : Select one: a.The peak input voltage b.The peak-to-peak input voltage minus 1 diode drop c.The peak-to-peak input voltage d.The peak input voltage minus 1 diode drop e.None of these

The peak input voltage

Diode limiters can be used to make a sine wave look more like a square wave, which is useful in communications circuits.

True

For small values of Vds the Id vs Vds curve for a MOSFET is linear, and looks just like a resistor.

True

For the diode circuit shown, if an X-Y plot is displayed with Vin on the X-axis and Vout on the Y-axis, then the clipping levels can be measured from the flat parts on the top and bottom of the curve.

True

For the diode circuit shown, the negative clipping level will stay about the same as Vbias is increased.

True

Heavily doped PN junctions break down at lower reverse voltages than lightly doped PN junctions.

True

Peak Detectors are often used to charge up a capacitor to the average value of an input signal.

false

In a rectifier the diodes only turn on for a short conduction interval every cycle to replace the charge which the filter capacitor supplied to the load while the diodes were turned off.

true

If a PMOS FET is biased with |Vgs| > |Vt| and |Vds| > |Vgs| - |Vt|, the device is in : Select one: a.Saturation b.None of these c.Sub-threshold d.Triode e.Cutoff

Saturation

A Voltage Doubler circuit requires two diodes and two capacitors.

True

A very simple large-signal model for a diode is that the diode will not conduct any current if its forward voltage drop is less than 0.7V, so it will not conduct any current in the reverse direction.

True

As the forward bias across a PN junction is increased, the potential barrier decreases.

True

As the forward bias across a PN junction is increased, the width of the depletion region decreases.

True

At room temperature (300°K) there is enough thermal energy to break some bonds and create electron-hole pairs.

True

For the diode circuit shown, if Vbias is reduced then : Select one: a.None of these b.The current flowing in the diodes will stay the same c.The small-signal voltage gain Vout/Vin will increase d.The negative clipping level for Vout will increase e.The positive clipping level for Vout will increase

None of these

If a diode at 75deg C with a constant bias current of 100uA has a forward voltage of 100mV across it, what will the voltage drop across this same diode be at 25deg C.

800mV

If a diode at 300K with a constant bias current of 10uA has a forward voltage of 700mV across it, what will the voltage drop across this same diode be if the bias current is increased to 1mA?

820mV

If a diode at 300°K with a constant bias current of 10μA has a forward voltage of 700mV across it, what will the voltage drop across this same diode be if the bias current is increased to 1mA?

820mV

Which of the following circuits is NOT part of a typical DC power supply? Select one: a.A voltage regulator b.A power transformer c.A diode rectifier d.None of these e.A high pass filter

A high pass filter

Which of the following circuits is part of a typical DC power supply? Select one: a.A diode limiter b.A current regulator c.None of these d.A load resistor e.A low pass filter

A low pass filter

Which of the following circuits is part of a typical DC power supply? Select one: a.A diode limiter b.A load resistor c.A voltage regulator d.A high pass filter e.All of these

A voltage regulator

In a Peak Detector diode circuit, which of the following is true? Select one: a.All of these b.The diode must have a breakdown voltage larger than the peak-to-peak input voltage c.The charge supplied to the load is replaced by the diode each time the input voltage reaches it's peak d.The diode turns on briefly in the beginning, but then is off most of the time e.The output voltage is equal to the maximum input voltage

All of these

Which of the following circuits is part of a typical DC power supply? Select one: a.A diode rectifier b.All of these c.A voltage regulator d.A low pass filter e.A power transformer

All of these

Which of the following is true ? Select one: a.All of these b.In intrinsic Silicon at 300°K the number of holes is far less than the number of Silicon atoms c.In intrinsic Silicon at 300°K there are some free electrons due to thermal generation d.In intrinsic Silicon at 300°K the number of holes is equal to the number of free electrons e.In intrinsic Silicon at 300°K both holes and electrons can conduct electricity

All of these

Which of the following is true ? Select one: a.In intrinsic Silicon at 300°K there are some free electrons due to thermal generation b.In intrinsic Silicon at 300°K the number of holes is far less than the number of Silicon atoms c.In intrinsic Silicon at 300°K both holes and electrons can conduct electricity d.All of these e.In intrinsic Silicon at 300°K the number of holes is equal to the number of free electrons

All of these

Which of the following is true about the small-signal model for a reverse biased diode? Select one: a.The reverse diode voltage equals the battery voltage plus the current times the incremental resistance b.The small-signal model is valid for reverse bias voltages > the knee voltage, Vzk c.The small-signal model is valid for reverse bias currents > the knee current, Izk d.All of these e.The incremental resistance of the diode can be measured from the slope of the diode I-V curve

All of these

Which of the following is true for the diffusion capacitance of a PN junction? Select one: a.The capacitance increases as the mean transit time increases b.The capacitance increases as the forward bias increases c.The amount of charge stored increases as the forward bias increases d.The capacitance decreases as temperature increases e.All of these

All of these

Which of the following is true ? Select one: a.Phosphorus is often used as a P-type dopant in Silicon b.Carbon is often used as a P-type dopant in Silicon c.None of these d.Boron is often used as an N-type dopant in Silicon e.Arsenic is often used as an N-type dopant in Silicon

Arsenic is often used as an N-type dopant in Silicon

In a half-wave rectifier the diode turns on twice during each period of the input sine wave to recharge the filter capacitor.

False

As the forward bias voltage across a PN junction is increased, the width of the depletion region will Select one: a.Increase b.No way to determine c.Decrease d.Stays the same e.None of these

Decrease

In a semiconductor doped with donor atoms, the number of holes is much higher than the number of electrons.

False

A Load Line analysis is a graphical solution method which allows a nonlinear set of simultaneous equations to be solved, by plotting the nonlinear equation for the circuit on the same plot with the diode's linear I-V characteristic curve.

FALSE

A simple approximation for the maximum |Vds| required in order for a MOSFET to be in saturation is |Vds-sat| = |Vgs| - |Vt|.

FALSE

As the reverse bias across a PN junction is decreased, the potential barrier increases.

FALSE

At absolute zero (0°K) there is still enough thermal energy to break some bonds and create electron-hole pairs.

FALSE

In a power supply diodes are typically used to rectify the AC input voltage, which means converting a unipolar sine wave into a series of bipolar pulses.

FALSE

The filter capacitor used to filter the output pulses from a diode rectifier in a power supply is typically quite large, often bigger than 10F.

FALSE

he depletion region capacitance increases linearly as the reverse bias voltage is decreased.

FALSE

As the forward bias across a PN junction is decreased, the potential barrier decreases.

False

As the forward bias across a PN junction is increased, the width of the depletion region increases.

False

Both electrons and holes are charge carriers which can form covalent bonds between atoms.

False

Both holes and electrons leave behind mobile ions when they conduct electricity.

False

For a Full Wave Rectifier the diodes must be able to handle a Peak Inverse Voltage equal to nearly the peak of the input voltage.

False

For a Half Wave Rectifier the diode must be able to handle a Peak Inverse Voltage equal to nearly twice the peak of the input voltage.

False

For a MOSFET in saturation, changes in Vds have only a small effect on the drain current because the channel stops being pinched off at the drain end as |Vds| is increased.

False

If the reverse bias voltage applied across a diode gets too high and exceeds the breadkdown voltage for the diode, then the forward current flowing though the diode will increase sharply.

False

If the reverse bias voltage applied across a diode gets too high and exceeds the breakdown voltage for the diode, then the forward current flowing though the diode will increase sharply.

False

In Peak Detector circuits, the diodes conduct current the majority of the time.

False

In a DC Restorer circuit, a diode typically clamps the output voltage as it tries to move in one direction, and prevents it from going much past the peak input voltage.

False

The threshold voltage of a MOSFET is the amount of voltage that must be applied between the drain and the source in order for a channel to be formed between the gate and the source.

False

To keep the parasitic PN junction diodes turned off in a CMOS process, the N-wells should be connected to the lowest supply voltage used on the IC.

False

To keep the parasitic PN junction diodes turned off in a CMOS process, the P-substrate should be connected to the highest supply voltage used on the IC.

False

To solve a nonlinear circuit equation by iteration, you should use exponentials instead of logarithms to aid in convergence.

False

Using the small-signal model for a diode is the best way to find the clipping levels for a circuit containing diodes.

False

When a forward bias current flows through a diode, the voltage across the diode will increase exponentially as the current through the diode increases linearly.

False

When p-type silicon is brought into contact with n-type silicon, holes diffuse from the N side to the P side, and electrons diffuse from the P side to the N side.

False

When silicon is doped with donor atoms, this increases the number of holes.

False

In a DC Restorer circuit, a capacitor forces a diode to charge up to either the positive or negative peak of the input signal.

False; only positive

Which of these circuits requires the diodes used to have the lowest peak inverse voltage rating? Select one: a.Same for all of these b.Impossible to determine c.Full-wave rectifiers using a bridge rectifier d.Full-wave rectifiers using a center-tapped transformer e.Half-wave rectifiers without a filter capacitor

Full-wave rectifiers using a bridge rectifier

The gate-to-drain voltage in a triode NMOS FET is : Select one: a.All of these b.Greater than the gate-to-channel voltage c.Greater than the gate-to-source voltage d.Greater than the threshold voltage e.None of these

Greater than the threshold voltage

Which of the following is true ? Select one: a.In intrinsic Silicon at 300°K there are no free electrons b.All of these c.In intrinsic Silicon at 300°K the number of free electrons is about equal to the number of Silicon atoms d.In intrinsic Silicon at 300°K both holes and electrons can conduct electricity e.In intrinsic Silicon at 300°K the number of holes is far less than the number of free electrons

In intrinsic Silicon at 300°K both holes and electrons can conduct electricity

Which of the following is true ? Select one: a.All of these b.In intrinsic Silicon at 300°K there are no free electrons c.In intrinsic Silicon at 300°K the number of holes is far less than the number of Silicon atoms d.In intrinsic Silicon at 300°K only free electrons can conduct electricity e.In intrinsic Silicon at 300°K the number of free electrons is about equal to the number of Silicon atoms

In intrinsic Silicon at 300°K the number of holes is far less than the number of Silicon atoms

Which of the following is true for the depletion region surrounding a PN junction? Select one: a.None of these b.In the depletion region there are immobile ions which cause a separation of charge c.In the depletion region there are almost no immobile ions d.In the depletion region there is zero electric field e.In the depletion region the amount of charge stored stays constant as the bias is varied

In the depletion region there are immobile ions which cause a separation of charge

Which of the following is true for the depletion region surrounding a PN junction? Select one: a.In the depletion region there are almost no immobile ions b.In the depletion region there are free electrons and holes which cause a separation of charge c.In the depletion region there is an electric field, which creates a barrier voltage d.All of these e.In the depletion region the amount of charge stored stays constant as the bias is varied

In the depletion region there is an electric field, which creates a barrier voltage

Which of the following would NOT cause the ripple voltage at the output of a power supply to increase? Select one: a.Reducing the frequency of the input voltage b.Reducing the size of the filter capacitor c.None of these d.Increasing the amplitude of the input voltage e.Increasing the size of the load resistance

Increasing the size of the load resistance

As the forward bias voltage across a PN junction is decreased, the potential barrier will Select one: a.No way to determine b.None of these c.Decrease d.Increase e.Stays the same

Increase

As the forward bias voltage across a PN junction is decreased, the width of the depletion region will Select one: a.No way to determine b.Increase c.None of these d.Stays the same e.Decrease

Increase

As the forward bias voltage across a PN junction is increased, the diffusion capacitance will Select one: a.Increase b.Stays the same c.No way to determine d.None of these e.Decrease

Increase

Compared to the mobility of holes in silicon, the mobility of electrons is : Select one: a.Smaller b.The same c.None of these d.Impossible to determine e.Larger

Larger

Compared to the process transconductance for a PMOS FET, the process transconductance for an NMOS FET is : Select one: a.None of these b.Larger c.Impossible to determine d.Smaller e.Same

Larger

If a diode at 25deg C with a constant bias current af 100uA has a forward voltage of 100mV across it, what will the voltage drop across this same diode be at 100deg C? a.) None of these b.) 650mV c.) 800mV d.) 600mV e.) 750mV

None of these

If a diode at 300°K with a constant bias current of 1mA has a forward voltage of 700mV across it, what will the voltage drop across this same diode be if the bias current is decreased to 1μA?Select one: a.760mV b.820mV c.640mV d.None of these e.580mV

None of these

The gate-to-drain voltage in a saturated NMOS FET is : Select one: a.Greater than the threshold voltage b.Greater than the gate-to-channel voltage c.Greater than the gate-to-source voltage d.All of these e.None of these

None of these

When P-type Silicon is brought into contact with N-type Silicon to form a PN Junction : Select one: a.The donor and acceptor atoms near the junction are free to conduct electricity b.The separation of charge causes an electric field which assists the diffusion of carriers c.Holes diffuse from the N side to the P side, and electrons diffuse from the P side to the N side d.None of these e.The area around the junction is depleted of immobile ions

None of these

Which of the following allows diode circuits to be analyzed without using any equations or plots? Select one: a.The constant voltage drop diode model b.Graphical analysis using a load line c.None of these d.The ideal diode model e.Iterative analysis using the exponential diode model

None of these

Which of the following allows diode circuits to be analyzed without using any equations or plots? a. Graphical analysis using a load line b. the constant voltage drop model c. None of these d. The idea diode model e. iterative analysis using the exponential diode model

None of these

Which of the following is true ? Select one: a.In intrinsic Silicon at 300°K the number of holes is far less than the number of free electrons b.None of these c.In intrinsic Silicon at 300°K there are no free electrons d.In intrinsic Silicon at 300°K only free electrons can conduct electricity e.In intrinsic Silicon at 300°K the number of free electrons is about equal to the number of Silicon atoms

None of these

Which of the following is true ? Select one: a.None of these b.Phosphorus has 3 electrons in its outermost shell c.Arsenic has 4 electrons in its outermost shell d.Boron has 5 electrons in its outermost shell e.Silicon has 5 electrons in its outermost shell

None of these

Which of the following would cause the ripple voltage at the output of a power supply to increase? Select one: a.Increasing the frequency of the input voltage b.Increasing the size of the filter capacitor c.Reducing the amplitude of the input voltage d.None of these e.Increasing the size of the load resistance

None of these

Which of the of the following is true for a diode with a voltage Vd applied to the P side and the N side grounded? Select one: a.The diode "turns on" and starts carrying a significant amount of current when Vd is < -0.5V b.None of these c.The current through the diode, Id, grows exponentially when Vd is decreased slightly below 0V d.The current through the diode, Id, grows linearly when Vd is increased slightly above 0V e.The current through the diode, Id, is approximately constant when Vd is decreased below the breakdown voltage

None of these

Which of the following is true ? Select one: a.All of these b.Phosphorus has 5 electrons in its outermost shell c.Silicon has 3 electrons in its outermost shell d.Arsenic has 4 electrons in its outermost shell e.Boron has 5 electrons in its outermost shell

Phosphorus has 5 electrons in its outermost shell

Which of the following is true ? Select one: a.Phosphorus is often used as an N-type dopant in Silicon b.Arsenic is often used as a P-type dopant in Silicon c.All of these d.Boron is often used as an N-type dopant in Silicon e.Carbon is often used as a P-type dopant in Silicon

Phosphorus is often used as an N-type dopant in Silicon

Which of the following would cause the ripple voltage at the output of a power supply to increase? Select one: a.Increasing the size of the load resistance b.Reducing the amplitude of the input voltage c.All of these d.Reducing the frequency of the input voltage e.Increasing the size of the filter capacitor

Reducing the frequency of the input voltage

Which of the following would cause the ripple voltage at the output of a power supply to increase? Select one: a.Reducing the size of the load resistance b.All of these c.Reducing the amplitude of the input voltage d.Increasing the size of the filter capacitor e.Increasing the frequency of the input voltage

Reducing the size of the load resistance

If an NMOS FET is biased with Vgs > Vt and Vds > Vgs - Vt, the device is in : Select one: a.Cutoff b.Triode c.Sub-threshold d.None of these e.Saturation

Saturation

As Vds is increased above Vgs - Vt in a saturated NMOS FET, the voltage across the channel : Select one: a.Increases b.Stays constant c.Decreases d.Impossible to determine e.None of these

Stays constant

A MOSFET enters the saturation region of operation when the gate-to-channel voltage at the drain end of the channel drops below the threshold voltage.

TRUE

For a Full Wave Rectifier the diodes must be able to handle a Peak Inverse Voltage equal to nearly twice the peak of the input voltage.

TRUE

In a power supply a large filter capacitor is typically used to smooth out the pulses from the rectifier to create a nearly constant output voltage, with only small variations called ripple.

TRUE

In a semiconductor doped with acceptor atoms, the number of holes is much higher than the number of electrons.

TRUE

The capacitance of a MOSFET's gate increases as the area of the gate increases.

TRUE

The process transconductance for a MOSFET, k' , is directly proportional to both the gate oxide capacitance and the carrier mobility, but doesn't depend on the W/L of the FET.

TRUE

For the diode circuit shown, at the positive clipping level : Select one: a.The D1 diode is off, and the D2 diode is on b.The D1 diode is on, and the D2 diode is off c.None of these d.The D1 diode is on, and the D2 diode is on e.The D1 diode is off, and the D2 diode is off

The D1 diode is off, and the D2 diode is on

For the diode circuit shown, in the middle of the signal swing : Select one: a.The D1 diode is on, and the D2 diode is off b.The D1 diode is off, and the D2 diode is on c.The D1 diode is off, and the D2 diode is off d.The D1 diode is on, and the D2 diode is on e.None of these

The D1 diode is on, and the D2 diode is on

To keep the parasitic PN junctions in a CMOS process turned off, which of the following must be done? Select one: a.The sources of the PMOS FETs must be connected to the highest voltage used on the integrated circuit b.None of these c.The N-wells must be connected to the lowest voltage used on the integrated circuit d.The P-substrate must be connected to the lowest voltage used on the integrated circuit e.The sources of the NMOS FETs must be connected to the lowest voltage used on the integrated circuit

The P-substrate must be connected to the lowest voltage used on the integrated circuit

Which of the following is true for the diffusion capacitance of a PN junction? Select one: a.The capacitance decreases as the mean transit time increases b.The capacitance increases as temperature increases c.The capacitance decreases as the forward bias increases d.The amount of charge stored increases as the forward bias increases e.All of these

The amount of charge stored increases as the forward bias increases

Which of the following is true for the depletion region capacitance of a PN junction? Select one: a.None of these b.The capacitance depends on the square root of the reverse bias for a linearly graded junction c.The capacitance depends on the cube root of the reverse bias for an abrupt step junction d.The capacitance decreases as the reverse bias decreases e.The amount of charge stored increases as the reverse bias increases

The amount of charge stored increases as the reverse bias increases

In a DC Restorer diode circuit, which of the following is true? Select one: a.All of these b.The capacitor clamps one side of the diode to a fixed voltage, such as ground c.The average value of the output voltage is not equal to zero d.The capacitor charges up to the average value of input voltage e.The peak-to-peak output voltage is equal to the peak input voltage

The average value of the output voltage is not equal to zero

In a DC Restorer diode circuit, which of the following is true? Select one: a.The capacitor charges up to the average value of input voltage b.The capacitor clamps one side of the diode to a fixed voltage, such as ground c.The average value of the output voltage is not equal to zero d.The peak-to-peak output voltage is equal to the peak input voltage e.All of these

The average value of the output voltage is not equal to zero

Which of the following is true for the depletion region capacitance of a PN junction? Select one: a.The capacitance decreases as the reverse bias increases b.The capacitance depends on the square root of the reverse bias for a linearly graded junction c.All of these d.The amount of charge stored decreases as the reverse bias increases e.The capacitance depends on the cube root of the reverse bias for an abrupt step junction

The capacitance decreases as the reverse bias increases

Which of the following is true for the depletion region capacitance of a PN junction? a.The amount of charge stored decreases as the reverse bias increases b.The capacitance decreases as the reverse bias decreases c.None of these d.The capacitance depends on the square root of the reverse bias for an abrupt step junction e.The capacitance depends on the square root of the reverse bias for a linearly graded junction Clear my choice

The capacitance depends on the square root of the reverse bias for an abrupt step junction

What happens to the gate capacitance of a MOSFET biased with |Vgs| > |Vt| as the |Vgs| increases? Select one: a.Impossible to determine b.The capacitance increases c.The capacitance doesn't change d.None of these e.The capacitance decreases

The capacitance doesn't change

What happens to the gate capacitance of a MOSFET biased with |Vgs| > |Vt| as the gate width increases? Select one: a.None of these b.The capacitance increases c.The capacitance doesn't change d.The capacitance decreases e.Impossible to determine

The capacitance increases

Which of the following is true for the diffusion capacitance of a PN junction? Select one: a.None of these b.The capacitance increases as temperature increases c.The capacitance decreases as the mean transit time increases d.The amount of charge stored decreases as the forward bias increases e.The capacitance increases as the forward bias increases

The capacitance increases as the forward bias increases

As Vds is increased above Vgs - Vt for a saturated NMOS FET : Select one: a.The channel becomes "pinched-off" near the drain b.None of these c.The capacitance of the drain PN junction gets larger d.The depletion region around the drain gets narrower e.The voltage across the channel increases

The channel becomes "pinched-off" near the drain

Which of the following is the best balance between ease of use and accuracy to quickly analyze diode circuits? Select one: a.Graphical analysis using a load line b.The constant voltage drop diode model c.The ideal diode model d.None of these e.Iterative analysis using the exponential diode model

The constant voltage drop diode model

Which of the following are true for a diode with a voltage Vd applied to the P side and the N side grounded?

The current through the diode Id grows linearly when Vd is decreased below the breakdown voltage.

When P-type Silicon is brought into contact with N-type Silicon to form a PN Junction : Select one: a.All of these b.The area around the junction is depleted of immobile ions c.Holes diffuse from the N side to the P side, and electrons diffuse from the P side to the N side d.The separation of charge causes an electric field which assists the diffusion of carriers e.The donor and acceptor atoms near the junction are ionized, leaving behind fixed charge

The donor and acceptor atoms near the junction are ionized, leaving behind fixed charge

When P-type Silicon is brought into contact with N-type Silicon to form a PN Junction : Select one: a.The area around the junction is depleted of free electrons and holes b.All of these c.The donor and acceptor atoms near the junction are ionized, leaving behind fixed charge d.The separation of charge causes an electric field which opposes the diffusion of carriers e.Holes diffuse from the P side to the N side, and electrons diffuse from the N side to the P side

The donor and acceptor atoms near the junction are ionized, leaving behind fixed charge

Which of the following is true for an NMOS FET? Select one: a.The channel is formed by attracting holes to the surface b.The threshold voltage is negative c.None of these d.The drain and source are doped N+ e.The body is doped N- Clear my choice

The drain and source are doped N+

Which of the following is true for a PMOS FET? Select one: a.All of these b.The body is doped P- c.The channel is formed by attracting electrons to the surface d.The drain and source are doped P+ e.The threshold voltage is positive

The drain and source are doped P+

Assuming ideal diodes, for the diode circuit shown : Select one: R+(D1+D2+RL In parallel) a.The maximum output voltage is -V1 b.The gain is equal to RL/(R+RL) when V is > +V1, or < -V2 c.The minimum output voltage is +V2 d.The gain is equal to RL/(R+RL) when V is < +V1 and > -V2 e.All of these

The gain is equal to RL/(R+RL) when V is < +V1 and > -V2

What happens to the gate-to-channel voltage in a saturated NMOS FET as you move from source to drain? Select one: a.The gate-to-channel voltage doesn't change b.The gate-to-channel voltage decreases c.The gate-to-channel voltage increases d.Impossible to determine e.None of these

The gate-to-channel voltage decreases

Which of the following is true for a semiconductor doped with Arsenic at 300°K ? Select one: a.The number of holes is less than the number of free electrons b.Both the number of holes and the number of free electrons are equal to zero c.The number of holes is greater than the number of free electrons d.All of these e.The number of holes is equal to the number of free electrons

The number of holes is less than the number of free electron

In a Peak Detector diode circuit, which of the following is true? Select one: a.The charge supplied to the load is replaced by the capacitor each time the input voltage reaches it's peak b.The diode must have a breakdown voltage equal to the peak input voltage c.None of these d.The output voltage is equal to the maximum input voltage e.The diode turns on briefly in the beginning, but then is on most of the time

The output voltage is equal to the maximum input voltage

In a Full-wave rectifier which uses a center-tapped transformer, the minimum breakdown voltage required for the diodes is : Select one: a.The peak input voltage minus 1 diode drop b.None of these c.The peak-to-peak input voltage d.The peak-to-peak input voltage minus 1 diode drop e.The peak input voltage

The peak-to-peak input voltage minus 1 diode drop

What happens to the channel resistance of a triode MOSFET as |Vgs| - |Vt| increases? Select one: a.None of these b.The resistance increases c.Impossible to determine d.The resistance decreases e.The resistance doesn't change

The resistance decreases

Which of the following is true for the small-signal resistance of a forward biased diode? Select one: a.The small-signal resistance of a diode models the resistance of the silicon used to build the diode b.None of these c.The small-signal resistance of a diode decreases as the temperature increases d.The small-signal resistance of a diode can be measured from the slope of the diode I-V curve e.The small-signal resistance of a diode increases as the bias current increases

The small-signal resistance of a diode can be measured from the slope of the diode I-V curve

Which of the following is true for the small-signal resistance of a forward biased diode? Select one: a.None of these b.The small-signal resistance of a diode is equal to the slope of the diode I-V curve c.The small-signal resistance of a diode increases as the bias current increases d.The small-signal resistance of a diode models the resistance of the silicon used to build the diode e.The small-signal resistance of a diode increases as the temperature increases

The small-signal resistance of a diode increases as the temperature increases

Which of the following is true for an NMOS FET? Select one: a.None of these b.The threshold voltage is positive c.The channel is formed by attracting holes to the surface d.The body is doped N- e.The drain and source are doped P+

The threshold voltage is positive

A Full Wave Rectifier allows both the positive and negative peaks of the input sine wave through to the output.

True

A Load Line analysis is a graphical solution method which allows a nonlinear set of simultaneous equations to be solved, by plotting the linear equation for the circuit on the same plot with the diode's nonlinear I-V characteristic curve.

True

In a power supply a transformer is typically used to reduce the high line voltage to a more useful, lower value.

True

In a rectifier the diodes only turn on for a short conduction interval every cycle to replace the charge which the filter capacitor supplied to the load while the diodes were turned off.

True

One of the most useful applications for diodes is in DC power supplies, which convert an AC input voltage into a DC output voltage.

True

PMOS FETs use P+ doped source and drain diffusions in a N-type substrate.

True

Silicon has 4 electrons in its outermost shell, which form covalent bonds with other atoms to form a crystal.

True

The Avalanche effect typically causes the reverse breakdown of PN junctions which break down at voltages > 7V.

True

The amount of charge stored on a MOSFET's gate capacitance is directly proportional to |Vgs| - |Vt|.

True

The amount of charge that is in the channel of a MOSFET at any particular point in the channel is directly proportional to the gate-to-channel voltage at that point in the channel.

True

The diffusion capacitance for a PN junction is directly proportional to the DC bias current for the junction.

True

The intrinsic carrier concentration for silicon is about 1.5 x 10^10/cm^3 at room temperature (300°K).

True

The output voltage for a bridge rectifier is just slightly lower than the output voltage for a full wave rectifier which uses a center-tapped transformer.

True

The simplest model to use when analyzing diode circuits is the Ideal Diode model, which assumes that the diode is a short circuit when forward biased and an open circuit when reverse biased.

True

The voltage across a forward biased silicon diode will change by about -2mV/°C as temperature changes.

True

Using a larger filter capacitor in a power supply will result in lower ripple, but cost more.

True

When a free electron moves away from it's donor atom, it leaves behind a positively charged ion.

True

When a hole moves away from it's acceptor atom, it leaves behind a negatively charged ion.

True

When is the current flowing through a diode approximately constant? Select one: a.None of these b.When the voltage on the P side is higher than the voltage on the N side c.When the voltage on the N side is higher than the voltage on the P side, and higher than the breakdown voltage d.When the voltage on the P side is higher than the voltage on the N side by at least 500mV e.When the voltage on the N side is higher than the voltage on the P side, but lower than the breakdown voltage

When the voltage on the N side is higher than the voltage on the P side, but lower than the breakdown voltage