Floyd Self-test in Thyristors

This is the Self-test in Chapter 11: Thyristors from the book Electronic Devices Conventional Current Version, 9th edition by Thomas L. Floyd. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam.

Floyd Self-test Chapter 11 Topic Outline

• Floyd Self-test in The Four-Layer Diode
• Floyd Self-test in The Silicon-Controlled Rectifier (SCR)
• Floyd Self-test in SCR Applications
• Floyd Self-test in The Diac and Triac
• Floyd Self-test in The Silicon-Controlled Switch (SCS)
• Floyd Self-test in The Unijunction Transistor (UJT)
• Floyd Self-test in The Programmable Unijunction Transistor (PUT)

If you are looking for the Multiple Choice Questions in Floyd’s Electronic Devices proceed to

Start Practice Exam Test Questions

Choose the letter of the best answer in each questions.

1. A thyristor has

(a) two pn junctions

(b) three pn junctions

(c) four pn junctions

(d) only two terminals

2. Common types of thyristors include

(a) BJTs and SCRs

(b) UJTs and PUTs

(c) FETs and triacs

(d) diacs and triacs

3. A 4-layer diode turns on when the anode-to-cathode voltage exceeds

(a) 0.7 V

(b) the gate voltage

(c) the forward-breakover voltage

(d) the forward-blocking voltage

4. Once it is conducting, a 4-layer diode can be turned off by

(a) reducing the current below a certain value

(b) disconnecting the anode voltage

(c) answers (a) and (b)

(d) neither answer (a) nor (b)

5. An SCR differs from the 4-layer diode because

(a) it has a gate terminal

(b) it is not a thyristor

(c) it does not have four layers

(d) it cannot be turned on and off

6. An SCR can be turned off by

(a) forced commutation

(b) a negative pulse on the gate

(c) anode current interruption

(d) answers (a), (b), and (c)

(e) answers (a) and (c)

7. In the forward-blocking region, the SCR is

(a) reverse-biased

(b) in the off state

(c) in the on state

(d) at the point of breakdown

8. The specified value of holding current for an SCR means that

(a) the device will turn on when the anode current exceeds this value

(b) the device will turn off when the anode current falls below this value

(c) the device may be damaged if the anode current exceeds this value

(d) the gate current must equal or exceed this value to turn the device on

9. The diac is

(a) a thyristor

(b) a bilateral, two-terminal device

(c) like two parallel 4-layer diodes in reverse directions

(d) answers (a), (b), and (c)

10. The triac is

(a) like a bidirectional SCR

(b) a four-terminal device

(c) not a thyristor

(d) answers (a) and (b)

11. The SCS differs from the SCR because

(a) it does not have a gate terminal

(b) its holding current is less

(c) it can handle much higher currents

(d) it has two gate terminals

12. The SCS can be turned on by

(a) an anode voltage that exceeds forward-breakover voltage

(b) a positive pulse on the cathode gate

(c) a negative pulse on the anode gate

(d) either (b) or (c)

13. The SCS can be turned off by

(a) a negative pulse on the cathode gate and a positive pulse on the anode gate

(b) reducing the anode current to below the holding value

(c) answers (a) and (b)

(d) a positive pulse on the cathode gate and a negative pulse on the anode gate

14. Which of the following is not a characteristic of the UJT?

(a) intrinsic standoff ratio

(b) negative resistance

(c) peak-point voltage

(d) bilateral conduction

15. The PUT is

(a) much like the UJT

(b) not a thyristor

(c) triggered on and off by the gate-to-anode voltage

(d) not a four-layer device

Complete List of Floyd Self-test in Electronic Devices

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