4th Year Review

Question 1

AND gate truth statement

Answer 1

Any low gives a low
A•B=Y

Question 2

OR gate truth statement

Answer 2

Any high gives a high
A+B=Y

Question 3

NAND gate truth statement

Answer 3

Any low gives a high
—-
A•B=Y

Question 4

NOR gate truth statement

Answer 4

Any high gives a low
——
A+B=Y

Question 5

NOT (inverter) gate truth statement

Answer 5

Output is opposite input
-
A=A

Question 6

XOR gate truth statement

Answer 6

A or B, not both
- -
A•B + A•B=Y

Question 7

What is the main outstanding feature of using ‘gray code’ for use with transducers?

Answer 7

Changes by one bit per position

Question 8

What is ASCII used for?

Answer 8

Coding computer inputs into binary
De-coding it back so we can understand

Question 9

When a flip-flop is preset it stores a binary __ (1 or 0)

Answer 9

1

Question 10

To set or clear a flip-flop, must the signlas applied to the PR and CLR inputs be permanent?

Answer 10

No

Question 11

Can a single flip-flop store more than one binary bit of data to Q?

Answer 11

No

Question 12

Which is considered the primary output of a flip-flop;
-
Q or Q?

Answer 12

Q

Question 13

When 1 is present at the Q output of a flip-flop, it is said to be in the _____ (set/reset) condition.

Answer 13

Set

Question 14

Another term used for a flip-flop being in the clear condition is that it is ______ (set/reset).

Answer 14

Reset

Question 15

By applying a low to the PR input the J-K flip-flop will be _____ (set/reset).

Answer 15

Set

Question 16

By applying a low to the CLR input the J-K flip flop will be _____ (set/reset)

Answer 16

Reset

Question 17

When J and K inputs are both 1, and an appropriate clock pulse occurs, what happens to the flip-flop’s Q input?

Answer 17

It changes

Question 18

What gate is this?

Answer 18

AND gate

Question 19

What gate is this?

Answer 19

OR gate

Question 20

What gate is this?

Answer 20

NAND gate

Question 21

What gate is this?

Answer 21

NOR gate

Question 22

What gate is this?

Answer 22

NOT (inverter) gate

Question 23

What gate is this?

Answer 23

XOR gate

Question 24

What is the expected input impedance of the ideal op-amp?

Answer 24

High

You want the input voltage to be amplified. If there were a low impedance path through the inputs there would be a volt drop and an incorrect input

Question 25

What is the expected output impedance of the ideal op-amp?

Answer 25

Low Once the voltage has been amplified you want that voltage to be seen across the load

Question 26

List two practical applications where you would find op-amps being used in real world equipment.

Answer 26

PLC’s VFD’s

Question 27

What does OP-AMP stand for?

Answer 27

Operational amplifier

Question 28

Is the following op-amp inverted or non inverted? What would be the equation to find gain?

Answer 28

Non inverted 50Kohm/1Kohm +1

Question 29

Is the following op-amp inverted or non inverted? What would be the equation to find gain?

Answer 29

Inverted 27Kohm/3.3Kohm

Question 30

An operational amplifier has two inputs. What are they called?

Answer 30

Inverting Non inverting

Question 31

What is the difference between open-loop and closed-loop operation of an op-amp?

Answer 31

Open loop - no feedback, high gain, unstable Closed loop - feedback, low gain, stable

Question 32

Not a question, just study this bitch

Answer 32

YAGA

Question 33

List a reason for using negative feedback when operating an op-amp.

Answer 33

Controls the gain without distortion

Question 34

What type of power supply is used for an op-amp?

Answer 34

DC dual voltage with a center reference

Question 35

Give two examples of process variables

Answer 35

Speed Position Fluid pressure Liquid level Liquid flow Temperature

Question 36

What is open loop?

Answer 36

Not automatic No feedback Requires operator

Question 37

What is closed loop?

Answer 37

Automatic Feedback No operator required

Question 38

What is a transducer?

Answer 38

Converts energy from one form to another

Question 39

List four types of linear motion sensors

Answer 39

Potentiometer Variable inductor Variable capacitor Variable differential transformer

Question 40

What are three common uses of sensors? (What do they detect?)

Answer 40

Motion Force Temperature Light Position Fluid pressure/flow

Question 41

What is a bonded wire strain gauge used to sense?

Answer 41

Force

Question 42

List three type of fluid pressure sensors

Answer 42

Bourdon tube Bellows Diaphram

Question 43

Which device consists of two dissimilar metals that when heated produce a small voltage?

Answer 43

Thermocouple

Question 44

Which feedback sensor would produce a small voltage when subjected to vibration?

Answer 44

Piezo electric crystal

Question 45

Which two signals does a comparator use to determine an error signal?

Answer 45

Set point Feedback

Question 46

What is the function of an actuator?

Answer 46

Converts electrical energy to; Motion Heat Light

Question 47

What does a solenoid do?

Answer 47

Provides linear motion

Question 48

What is a sensor?

Answer 48

Measures and senses the process variable and provides feedback to the controller

Question 49

What type of sensor is this?

Answer 49

Linear motion potentiometer. Works with both AC and DC

Question 50

What type of sensor is this?

Answer 50

Linear motion variable inductor. Works with AC only

Question 51

What is an actuator?

Answer 51

A device that converts an input signal into mechanical motion

Question 52

What is the process variable?

Answer 52

A variable that needs to be controlled

Question 53

What is the set point?

Answer 53

The desired value of the process variable

Question 54

Who has the authority or jurisdiction of emergency and exit installations?

Answer 54

CEC - general wiring of installation NBC - governs where equipment is required

Question 55

Briefly describe standby power supply

Answer 55

A reliable source of power that is available either automatically or manually to maintain current supply to essential loads

Question 56

List four different places that commonly use a standby power supply

Answer 56

Hospitals Schools Airports Shopping centers

Question 57

What are UPS systems usually used for?

Answer 57

Provide backup power to critical loads Provides power conditioning to sensitive loads

Question 58

What are the two main classifications of UPS systems?

Answer 58

Online and offline

Question 59

What is the difference between the two classifications of UPS systems?

Answer 59

Online: zero transfer time as the charger, batteries and inverter are always supplying the load Offline: short transfer time as the static transfer switch goes from normal power to battery and inverter supplying the load