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Schematic Diagrams – Relay School

Total questions: 58

Worksheet time: 29mins

Name
Class
Date
1.

What is a one line diagram an overview of?

a)

The substation

b)

The control circuits

c)

The panel wiring

d)

The drawing revisions

2.

The AC Schematic shows in more detail all three phases and neutral connections of AC voltage and current circuits.

a)

True

b)

False

3.

Fill in the blank: The DC Schematic shows in more detail the control circuits including _______, closing, and alarms.

a)

tripping

b)

switching

c)

monitoring

d)

signaling

4.

What does the panel wiring diagram identify?

a)

The substation overview

b)

The actual wiring on a panel

c)

The control circuits

d)

The drawing revisions

5.

Utilities may have different methods to identify areas of the drawings that have been revised including _______.

a)

circling, cross hatching, etc.

b)

highlighting, underlining, etc.

c)

color coding, numbering, etc.

d)

doodling, sketching, etc.

6.

A phasor is a representation of a complex number used in electrical engineering to represent sinusoidal functions.

a)

A type of resistor

b)

A representation of a complex number used in electrical engineering

c)

A unit of frequency

d)

A type of capacitor

7.

The purpose of using phasor diagrams is to:

a)

visualize complex numbers in electrical engineering

b)

measure the speed of light

c)

calculate gravitational force

d)

determine chemical reactions

8.

What is the frequency of the United States power system?

a)

50 Hz

b)

60 Hz

c)

70 Hz

d)

80 Hz

9.

Refer to the typical balanced 3 phase current waveform and equivalent phasor diagram shown in fig. 2. What is the phase relationship between the currents using the phasor diagram?

a)

The currents are in phase

b)

The currents are 120 degrees apart

c)

The currents are 90 degrees apart

d)

The currents are 180 degrees apart

10.

In a CT circuit, how can the residual current be found using phasors?

a)

By measuring the phase difference between current and voltage

b)

By summing the phasors of all currents

c)

By calculating the vector sum of all phase currents

d)

By using the RMS value of the current

11.

What does the symbol 'T' stand for in schematic diagrams?

a)

Transformer

b)

Transistor

c)

Trip coil

d)

Timer

12.

Fill in the blank: The symbol 'Th' represents a _______ in schematic diagrams.

a)

Transformer (high voltage side)

b)

Transistor

c)

Thermistor

d)

Thyristor

13.

What is the meaning of the symbol 'TM' in schematic diagrams?

a)

A) Timer

b)

B) Telemetering

c)

C) Trip coil

d)

D) Transistor

14.

Fill in the blank: The symbol 'U' stands for _______ in schematic diagrams.

a)

Unit

b)

Universal

c)

Uranium

d)

Utility

15.

What does the symbol 'BK' denote in the main device parts?

a)

A) Brake

b)

B) Breaker

c)

C) Battery

d)

D) Base

16.

Fill in the blank: The symbol 'C' represents a _______ in the main device parts.

a)

Coil or capacitor

b)

Resistor

c)

Inductor

d)

Transistor

17.

What is the meaning of the symbol 'HC' in the main device parts?

a)

A) Heat coil

b)

B) Holding coil

c)

C) High current

d)

D) Hydraulic control

18.

The symbol 'SI' stands for _______ in the main device parts.

a)

Seal-in

b)

System Integration

c)

Signal Input

d)

Standard Interface

19.

What does the symbol 'TC' denote in the main device parts?

a)

A) Trip coil

b)

B) Timer coil

c)

C) Transformer coil

d)

D) Transistor coil

20.

Fill in the blank: The symbol 'V' represents a _______ in the main device parts.

a)

Valve

b)

Voltage

c)

Vector

d)

Volume

21.

What does the letter 'A' stand for in the schematic diagrams?

a)

A) Accelerating or automatic

b)

B) Blocking or back-up

c)

C) Close or cold

d)

D) Drop out

22.

What does the letter 'B' stand for in the schematic diagrams?

a)

A) Blocking or back-up

b)

B) Decelerating, down or disengaged

c)

C) Emergency or engaged

d)

D) Failure or forward

23.

What does the letter 'C' stand for in the schematic diagrams?

a)

Close or cold

b)

Hot or high

c)

Left, local, low, lower or leading

d)

Manual

24.

What does the letter 'D' stand for in the schematic diagrams?

a)

Decelerating, down or disengaged

b)

Emergency or engaged

c)

Failure or forward

d)

High speed

25.

What does the letter 'E' stand for in the schematic diagrams?

a)

Emergency or engaged

b)

Failure or forward

c)

Hand reset

d)

Instantaneous

26.

What does the letter 'F' stand for in the schematic diagrams?

a)

A) Failure or forward

b)

B) High speed

c)

C) Left, local, low, lower or leading

d)

D) Manual

27.

What does the letter 'H' stand for in the schematic diagrams?

a)

A) Hot or high

b)

B) Instantaneous

c)

C) Manual

d)

D) Off

28.

What does the letter 'HS' stand for in the schematic diagrams?

a)

High speed

b)

Left, local, low, lower or leading

c)

Manual

d)

Off

29.

What does the letter 'I' stand for in the schematic diagrams?

a)

A) Instantaneous

b)

B) Manual

c)

C) Off

d)

D) On

30.

What does the letter 'L' stand for in the schematic diagrams?

a)

A) Left, local, low, lower or leading

b)

B) Manual

c)

C) Off

d)

D) On

31.

What does the letter 'M' stand for in the schematic diagrams?

a)

A) Manual

b)

B) Off

c)

C) On

d)

D) Polarizing

32.

What does the letter 'OFF' stand for in the schematic diagrams?

a)

A) Off

b)

B) On

c)

C) Polarizing

d)

D) Pick up

33.

What does the letter 'ON' stand for in the schematic diagrams?

a)

A) On

b)

B) Polarizing

c)

C) Pick up

d)

D) Right, raise, reclosing, receiving, remote or reverse.

34.

What does the letter 'P' stand for in the schematic diagrams?

a)

A) Polarizing

b)

B) Pick up

c)

C) Right, raise, reclosing, receiving, remote or reverse

d)

D) Sending or Swing

35.

What does the letter 'PU' stand for in the schematic diagrams?

a)

A) Pick up

b)

B) Right, raise, reclosing, receiving, remote or reverse

c)

C) Sending or Swing

d)

D) Test, trip, trailing or time.

36.

What does the letter 'R' stand for in the schematic diagrams?

a)

A) Right, raise, reclosing, receiving, remote or reverse

b)

B) Sending or Swing

c)

C) Test, trip, trailing or time

d)

D) Test switch.

37.

What does the letter 'S' stand for in the schematic diagrams?

a)

A) Sending or Swing

b)

B) Test, trip, trailing or time

c)

C) Test switch

d)

D) Time delay

38.

What does the letter 'T' stand for in the schematic diagrams?

a)

A) Test, trip, trailing or time

b)

B) Test switch

c)

C) Time delay

d)

D) Time delay closing (TDPU)

39.

What does the letter 'TS' stand for in the schematic diagrams?

a)

A) Test switch

b)

B) Time delay

c)

C) Time delay closing (TDPU)

d)

D) Time delay opening (TDDO)

40.

What does the letter 'TD' stand for in the schematic diagrams?

a)

A) Time delay

b)

B) Time delay closing (TDPU)

c)

C) Time delay opening (TDDO)

d)

D) Zone

41.

What does the letter 'TDC' stand for in the schematic diagrams?

a)

A) Time delay closing (TDPU)

b)

B) Time delay opening (TDDO)

c)

C) Zone

d)

D) Accelerating or automatic.

42.

What does the letter 'TDO' stand for in the schematic diagrams?

a)

A) Time delay opening (TDDO)

b)

B) Zone

c)

C) Accelerating or automatic

d)

D) Blocking or back-up

43.

What does the letter 'U' stand for in the schematic diagrams?

a)

Up

b)

Zone

c)

Accelerating or automatic

d)

Blocking or back-up

44.

What does the letter 'Z' stand for in the schematic diagrams?

a)

Zone

b)

Accelerating or automatic

c)

Blocking or back-up

d)

Close or cold

45.

What are the phase identification letters for the North American convention?

a)

A) A, B, C

b)

B) R, S, T

c)

C) 1, 2, 3

46.

What are the phase identification letters for the Older European convention?

a)

A) R, S, T

b)

B) A, B, C

c)

C) 1, 2, 3

47.

What are the phase identification numbers for the Present European convention?

a)

A) 1, 2, 3

b)

B) A, B, C

c)

C) R, S, T

48.

What is the output of the 'AND' function when both inputs are 1?

a)

a) 0

b)

b) 1

49.

What is the output of the 'OR' function when both inputs are 0?

a)

0

b)

1

50.

What is the output of the 'NAND' function when both inputs are 1?

a)

0

b)

1

51.

What is the output of the 'NOR' function when both inputs are 0?

a)

0

b)

1

52.

What is the output of the 'Exclusive OR' function when both inputs are 1?

a)

0

b)

1

53.

What is the output of the 'INVERT' or 'NOT' function when the input is 0?

a)

0

b)

1

54.

The purpose of the M.R.C.T. 600/5 in the schematic diagram is:

a)

To provide power supply

b)

To measure current

c)

To control voltage

d)

To act as a fuse

55.

Identify the component labeled 'TS' in the schematic diagram and explain its function.

a)

Transistor - It amplifies current.

b)

Transformer - It transfers electrical energy between circuits.

c)

Thermistor - It changes resistance with temperature.

d)

Thyristor - It acts as a switch.

56.

In the schematic diagram, what does the symbol 'TRIPS S101, S102, S106' indicate?

a)

It indicates a power failure.

b)

It indicates a circuit breaker trip.

c)

It indicates a system overload.

d)

It indicates a maintenance alert.

57.

Which component in the schematic diagram is responsible for the alternate source?

a)

Transformer

b)

Generator

c)

Inverter

d)

Battery

58.

The role of the 'BANK #1' in the schematic diagram is to:

a)

store electrical energy

b)

convert AC to DC

c)

amplify signals

d)

regulate voltage