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Module 4 Electronic Fundamentals Exam 1 1.

What gives the colour of an LED? a) b) c)

2.

A germanium diode is used for a) b) c)

3.

To protect it from AC So it will work only above a certain voltage So it will work only below a certain voltage

When testing the forward bias of a diode with a multimeter a) b) c)

5.

rectification voltage stabilization modulation

Why is a diode put in parallel with an LED? a) b) c)

4.

The plastic it is encased in The active element The type of gas used inside it

the positive lead of the ohmeter is placed on the cathode the positive lead of the ohmeter is placed on the anode it does not matter which terminal the positive lead of the ohmeter is placed

In an NPN transistor the P is the a) b) c)

collector base emitter

6.

The output of a tachogenerator is a) b) c)

7.

AC power is supplied to a) b) c)

8.

torque receiver only torque transmitter only both the torque receiver and torque transmitter

This is a diagram of

a) b) c) 9.

proportional to speed of rotation proportional to position proportional to acceleration

a TRIAC an SCR a Schottky diode

How is a PCB protected after manufacture? a) b) c)

With non-conductive varnish With wax By conformal coating

10. A differential synchro a) b) c)

can only be used as a transmitter can only be used as a receiver can be used as either a transmitter or a receiver

Answers for Exam 1 Question 1

b

The active element is the element used in the doping of the semiconductor material. Aircraft Electricity and Electronics 5th Edition Eismin Page 121

Question 2

a

Germanium diode has the least forward bias voltage drop and is best for rectification

Question 3

a

An LED has a high forward bias voltage drop but is easily damaged when reverse biased. AC is therefore not good for an LED

Question 4

b

To test forward bias, the positive lead of the multimeter must be placed on the anode. Note: If the question says 'moving coil meter' then it would be the negative lead on the anode, since the negative side of the battery in such a meter is connected to the + lead. Aircraft Electricity and Electronics 5th Edition Eismin Page 113

Question 5

b

NPN or PNP, the middle one is always the Base. Aircraft Electricity and Electronics 5th Edition Eismin Page 116

Question 6

a

Read up on tachogenerators

Question 7

c

Read up on torque synchros

Question 8

b

You just have to know the different types of semiconductor applications Aircraft Electricity and Electronics 5th Edition Eismin Page 120

Question 9

c

Although varnish is often used on PCBs, 'conformal coating' is the name of the process usually applied to aircraft use PCBs. Aircraft Electricity and Electronics 5th Edition Eismin Page 122

Question 10 c

The TDX is a transmitter, the TDR is a receiver