Question 1

An equivalent circuit for a UJT is back- to back npn and pnp transistors.

Accepted Answer

A) True 
 B)False  False

Question 2

The forward- blocking region of a four- layer diode is from 0 V to VAK = VBR(F).

Accepted Answer

A) True 
 B)False  True

Question 3

A diac will stop conducting if

Accepted Answer

A) the peak of the applied waveform is reached 
B) low- current dropout occurs 
C) it receives a negative gate voltage 
D) all of the above 
A) the peak of the applied waveform is reached 
B) low- current dropout occurs 
C) it receives a negative gate voltage 
D) all of the above B

Question 4

A SCR can be turned on

Accepted Answer

A) by exceeding the forward breakover voltage 
B) by forced commutation 
C) both A and B 
D) none of the above 
A) by exceeding the forward breakover voltage 
B) by forced commutation 
C) both A and B 
D) none of the above

Question 5

To stop conduction in an SCR, you could

Accepted Answer

A) remove gate current 
B) apply a negative pulse to the gate 
C) both A and B 
D) none of the above 
A) remove gate current 
B) apply a negative pulse to the gate 
C) both A and B 
D) none of the above

Question 6

Figure 5
-Refer to Figure 5. If the value of R3 is reduced, the output amplitude will _ and the frequency will .

Accepted Answer

A) decrease, increase 
B) decrease, decrease 
C) increase, decrease 
D) increase, increase 
A) decrease, increase 
B) decrease, decrease 
C) increase, decrease 
D) increase, increase

Question 7

Figure 5
-Refer to Figure 5. The signal you expect to see on the oscilloscope is a

Accepted Answer

A) sine wave 
B) a square wave 
C) modified sawtooth wave 
D) series of positive trigger pulses 
A) sine wave 
B) a square wave 
C) modified sawtooth wave 
D) series of positive trigger pulses

Question 8

A triac is essentially a bidirectional electronic switch.

Accepted Answer

A) True 
 B)False

Question 9

A device that can be triggered on or off is

Accepted Answer

A) a triac 
B) an SCS 
C) both A and B 
D) none of the above 
A) a triac 
B) an SCS 
C) both A and B 
D) none of the above

Question 10

A diac is equivalent to two back- to- back inverted

Accepted Answer

A) triacs 
B) four- layer diodes 
C) SCRs 
D) SCSs 
A) triacs 
B) four- layer diodes 
C) SCRs 
D) SCSs

Question 11

The forward breakover voltage for an SCR

Accepted Answer

A) is a constant quantity specified by the manufacturer 
B) is proportional to VAK 
C) is dependent on the maximum specified anode current 
D) decreases for increasing IG 
A) is a constant quantity specified by the manufacturer 
B) is proportional to VAK 
C) is dependent on the maximum specified anode current 
D) decreases for increasing IG

Question 12

The voltage drop across a conducting SCR

Accepted Answer

A) is half the load voltage 
B) is a small negative voltage 
C) follows the input voltage 
D) is low 
A) is half the load voltage 
B) is a small negative voltage 
C) follows the input voltage 
D) is low

Question 13

Figure 1
-Refer to Figure 1. The type of device that is illustrated by this structure is

Accepted Answer

A) an SCS 
B) a UJT 
C) a diac 
D) none of the above 
A) an SCS 
B) a UJT 
C) a diac 
D) none of the above

Question 14

LASCR stands for low- amplitude silicon controlled rectifier.

Accepted Answer

A) True 
 B)False

Question 15

A diac can conduct current in either direction.

Accepted Answer

A) True 
 B)False

Question 16

The number of pn junctions in a UJT is

Accepted Answer

A) zero 
B) one 
C) two 
D) three 
A) zero 
B) one 
C) two 
D) three

Question 17

Increasing the firing angle in an SCR control circuit

Accepted Answer

A) increases the SCR current 
B) increases the holding current 
C) increases the output current 
D) none of the above 
A) increases the SCR current 
B) increases the holding current 
C) increases the output current 
D) none of the above

Question 18

The characteristic of a UJT that determines its turn- on point is called the

Accepted Answer

A) blocking point 
B) standoff ratio 
C) forward breakover voltage 
D) trigger current 
A) blocking point 
B) standoff ratio 
C) forward breakover voltage 
D) trigger current

Question 19

The purpose of an SCR crowbar circuit is to protect a load in case of

Accepted Answer

A) an open circuit 
B) overvoltage 
C) power failure 
D) all of the above 
A) an open circuit 
B) overvoltage 
C) power failure 
D) all of the above

Question 20

The IH specification is the highest allowed current in a thyristor.

Accepted Answer

A) True 
 B)False

An equivalent circuit for a UJT is back- to back npn and pnp transistors.

The forward- blocking region of a four- layer diode is from 0 V to VAK = VBR(F).

A diac will stop conducting if

A SCR can be turned on

To stop conduction in an SCR, you could

Figure 5 -Refer to Figure 5. If the value of R3 is reduced, the output amplitude will _ and the frequency will .

Figure 5 -Refer to Figure 5. The signal you expect to see on the oscilloscope is a

A triac is essentially a bidirectional electronic switch.

A device that can be triggered on or off is

A diac is equivalent to two back- to- back inverted

The forward breakover voltage for an SCR

The voltage drop across a conducting SCR

Figure 1 -Refer to Figure 1. The type of device that is illustrated by this structure is

LASCR stands for low- amplitude silicon controlled rectifier.

A diac can conduct current in either direction.

The number of pn junctions in a UJT is

Increasing the firing angle in an SCR control circuit

The characteristic of a UJT that determines its turn- on point is called the

The purpose of an SCR crowbar circuit is to protect a load in case of

The IH specification is the highest allowed current in a thyristor.

Introduction to Semiconductors

Diodes and Applications

Special-Purpose Diodes

Bipolar Junction Transistors

Transistor Bias Circuits

BJT Amplifiers

BJT Power Amplifiers

Field-Effect Transistors Fets

Fet Amplifiers and Switching Circuits

Amplifier Frequency Response

The Operational Amplifier

Basic Op-Amp Circuits

Special-Purpose Integrated Circuits

Active Filters

Oscillators

Voltage Regulators

Communication Devices and Methods

Filters

Exam 11: Thyristors

An equivalent circuit for a UJT is back- to back npn and pnp transistors.

The forward- blocking region of a four- layer diode is from 0 V to VAK = VBR(F).

A diac will stop conducting if

A SCR can be turned on

To stop conduction in an SCR, you could

Figure 5 -Refer to Figure 5. If the value of R3 is reduced, the output amplitude will _ and the frequency will .

Figure 5 -Refer to Figure 5. The signal you expect to see on the oscilloscope is a

A triac is essentially a bidirectional electronic switch.

A device that can be triggered on or off is

A diac is equivalent to two back- to- back inverted

The forward breakover voltage for an SCR

The voltage drop across a conducting SCR

Figure 1 -Refer to Figure 1. The type of device that is illustrated by this structure is

LASCR stands for low- amplitude silicon controlled rectifier.

A diac can conduct current in either direction.

The number of pn junctions in a UJT is

Increasing the firing angle in an SCR control circuit

The characteristic of a UJT that determines its turn- on point is called the

The purpose of an SCR crowbar circuit is to protect a load in case of

The IH specification is the highest allowed current in a thyristor.

Introduction to Semiconductors

Diodes and Applications

Special-Purpose Diodes

Bipolar Junction Transistors

Transistor Bias Circuits

BJT Amplifiers

BJT Power Amplifiers

Field-Effect Transistors Fets

Fet Amplifiers and Switching Circuits

Amplifier Frequency Response

The Operational Amplifier

Basic Op-Amp Circuits

Special-Purpose Integrated Circuits

Active Filters

Oscillators

Voltage Regulators

Communication Devices and Methods

Filters