1 Name at least three types of diodes.

Zener diode; Schottky diode; LED

2 What is a dynamic resistance?

Dynamic resistance of the diode is the resistance for an AC source deppending of the DC polarization of the diode.

3 Define rectification.

Makes an alternating signal unidirectional

4 Name the types of rectifiers.

Half-wave rectifier and full-wave rectifier

5 Sketch the half-wave rectifier output waveform

6What is the percentage voltage efficiency of a half-wave rectifier?

$$\frac{1}{\pi}x100\% \approx 31,8\%$$

7 Both types of full-wave rectifiers show the same efficiency (true or false)

True

8 Sketch the full-wave rectifier output waveform.

9 What is the simplest capacitor-input filter?

A capacitor connected parallel to the load resistor

10 In which type of rectifier the capacitor discharge time is shorter?

Full-wave rectifier

11Sketch a Zener diode symbol and label the terminals.

12 Identify each of following parameters: (a) Uf (b) Ir (c) Uz

Uf – forward voltage; Ir – reverse current; Uz – Zener voltage;

13 Zener diodes are normally operated in the breakdown region (true or false)

False

14 Define stabilization

Automatically maintain a constant voltage level

albo

Constant voltage across the output terminals as input voltage varies(within reasonable limits)

15 Which bias condition is normal for the variable capacitance diode?

Reverse-biased

16 What is the purpose of a variable capacitance diode?

Used mainly in systems of automatic voltage tuning in resonant circuirts

17 What type of junction is used in the Schottky diode?

M-S junction

18 The Schottky diode operates on majority or minority carriers?

Majority carriers

19 What metals are used in Schottky diode?

Semiconductor: gold; silver; platinum;

20 What is the main feature of the Schottky diode?

High frequency; rectify very high frequency signals

21Which bias condition produces light emission in a LED?

Forward-biased

22 What energy conversion occurs in a LED?

Electrical energy to optical energy

23 What process is responsible for light emission in a LED?

Emits a stream of photons

24 A photodiode operates in reverse bias.

Reverse

25 Name the current in the not-illuminated photodiode.

Dark current