MODULE 4[EASA Ref.4.1]a ELECTRONIC FUNDAMENTALS SEMICONDUCTORS

1.what is the characteristic of a diodes connected in series ?

• a. The current must be the same of each diodes.

• b.the current must be divided between diodes.

• c.the voltage drop at each diodes is equal to supply voltage.

2.What are the 2 materials commonly used as semiconductors

• a.rubber and tin

• b.copper and alliminium

• c.germanium and silicon

3.what are the majority carrier in the p-type semiconductor?

• a.electron

• b.holes

• c.nucleus

4.The terms flow of electron from negative supply to positive and holes moving in opposite direction is known as……..

• a.Reverse Bias

• b.depletion layer

• c.Forward Bias

5..Due to intrinsic conduction that produce minority carriers causes tiny current to flow across the P-N junction and is known as……

• a.barrier potentia

• b.depletion layer

• c.leakage current

6.what is the average output voltage of a Single Phase Full Wave Rectifier ?

• a.0.318 x peak

• b.0.637 x peak

• c.1.717 x peak

7.what are the advantages having Bridge rectifier compare to Single phase full wave rectifier?

• a.cheap and last longer

• b.required centre tap which is good as voltage doubler.

• c.transformer does not required to produce a double voltage secondary is only used.instead

8.to prevent arching and act as a safety device in a control switch contact…..

• a.zener diode

• b.free wheel diode

• c.thyristor diode.

9.what is the purpose of zener diodes and how it is connected

• a.used as a voltage stabilizer or constant voltage connected as reverse bia

• .used as aircraft transistozed regulator and protection system connectedforward bias

• c.as a constant voltage stabilizer and connected as forward bias

10.which of the following best describe as a Silicon controlled rectifier[THYRISTOR].

• a.PNP TRANSISTOR

• b.NPN TRANSISTOR

• c.4 layer silicon P and Nsemiconductors