Unit 2 diode

1. What is a diode?

Listening

5.

9. False

10. True

11. True

12. True

13. False

14. False

15. False

16. False

Reading

7.

1) forward biased

2) reverse biased

3) amount

4) diode

5) forward voltage drop

6) backward

7) peak inverse voltage

8) current

Vocabulary

8.

diode диод	p-n juction электро-дырочный переход	anode анод	forward bias прямое смещение	reverse voltage обратное напряжение
cathode катод	current rating номинальный ток	lead подводящий провод	circuit цепь	threshold порог

2. Creating a p-n junction

Start here

1.

1) b)

2) c)

3) a)

a) a p-n junction

b) forward bias

c) reverse bias

In the diagrams a-c:

• n-type region is red

• p-type region is blue

• electrons are black

• holes are white

3. Types of diodes

Test yourself

2.

1. Step Recovery Diode (SRD)

2. Gunn diode

3. Zener diode

4. Point-contact diode

5. Constant-current diodes

6. Transient Voltage Supression (TVS) diode

7. Super barrier diodes

8. Tunnel diode

9. Infrared (IR) LED

3.

7. a)

8. b)

9. a)

10. b)

11. a)

12. b)

4.

Diode Light - emitting diode (LED) Schottky diode Tunnel diode Photodiode Varicap Zener diode Transient voltage suppression (TVS) diode

4. DIODE APPLICATIONS

1.

1) c)

2) a)

3) b)

4.

8. d)

9. c)

10. e)

11. f)

12. a)

13. b)

14. g)

UNIT 3

TRANSISTOR

1. WHAT DOES A TRANSISTOR ACTUALLY DO?

Revision

6.

1) d)

2) b), c)

3) a), c)

4) b)

5) a)

6) b), c)

7) b), d)

8) a)

9) d)

2. TYPES OF TRANSISTORS AND HOW THEY WORK

Listening

2.

1) True

2) False

3) False

4) False

5) True

6) True

7) False

8) True

9) True

Vocabulary

3.

1) base

2) emitter

3) collector

4) negative

5) positive

6) emitter

7) collector

8) base

9) base

10) base

Task

4.

1) Vce

2) Ice

3) Vbe

4) Ibe

Reading

5.

1) b)

2) a)

In diagrams:

• N-type region is red

• P-type region is blue

• Holes are pluses, white

• Electrons are minuses, black

6.

1) E

2) H

3) D

4) G

5) A

6) B

7) F

8) C

3. Transistors in computers who invented the transistror?

Grammar

5.

1) do not need

2) works

3) does all this help

4) compares

5) gives

6) makes

7) have

8) is

Scanning

8.

1) Vacuum tubes were used before transistors.

2) Vacuum tubes had to warm up before they worked (and sometimes overheated when they did), they were unreliable and bulky and they used too much energy.

3) Three brilliant US physicists: John Bardeen (1908–1991), Walter Brattain (1902–1987), and William Shockley (1910–1989) invented the transistor.

4) Transistors were invented at Bell Laboratories in New Jersey in 1947.

5) It's no exaggeration that transistors have enabled some of humankind's biggest leaps in technology.

6) Bardeen, Brattain, and Shockley shared the world's top science award, the 1956 Nobel Prize in Physics, for their discovery.

UNIT 4