SLevel1Mixed

Name:

SLevel1Mixed

Multiple Choice
Identify the choice that best completes the statement or answers the question.

a.	See Above	d.	See Above
b.	See Above	e.	See Above
c.	See Above

a.	See Above	d.	See Above
b.	See Above	e.	See Above
c.	See Above

Multiple Response
Identify one or more choices that best complete the statement or answer the question.

Task No.:		Point(s):	2	Two answers are correct.	Cat. No.
Which statements about the performance data of a DC solenoid coil, as shown in the table below, are correct?
A	The limits for coil voltage are Vminimum = 21.6 V and Vmaximum = 26.4 V. The longer the average pickup time of the solenoid coil, the shorter the response time of the actuated directional control valve. The degree of protection indicates how well the solenoid coil is protected against overloading. The duty cycle indicates that the solenoid may be energized throughout the entire duration of the operation. The power consumption increases if the applied voltage decreases.
B
C
D
E

Coil Type      DC voltage

      Voltage      24 V
      Voltage fluctuation      max. ± 10 %
      Power consumption for 24 V      4.1 W
      Duty cycle      100 %
      Degree of protection      IP 65
      Ambient temperature      5 – 40 °C
      Medium temperature      10 – 60 °C
      Average pickup time      10 ms

Task No.:		Point(s):	2	Two answers are correct.	Cat. No.
Which statements about the functionality of the DC power supply, as shown below, are correct?
A	The diodes D1 and D3 conduct during the positive half-cycle, while diodes D2 and D4 conduct during the negative half-cycle of V1. The diodes D2 and D4 conduct during the positive half-cycle, while diodes D1 and D3 conduct during the negative half-cycle of V1. The diodes D1 and D2 conduct during the positive half-cycle, while diodes D3 and D4 conduct during the negative half-cycle of V1. After rectification and filtering, the purpose of the voltage regulator is to keep the DC output voltage constant and independent of load and supply variations. If the signal waveform to be rectified is 50 Hz, the ripple frequency is also 50 Hz.
B
C
D
E

Task No.:	Point(s):	1	One answer is correct.	Cat. No.
The unspecified meter reading in the electrical circuit, as shown below, is …

Task No.:		Point(s):	2	One answer is correct.	Cat. No.
For the seven-segment LED indicator, as shown below, several measurements with respect to ground are taken. Which number is displayed?
A	The number “0” is displayed. The number “1” is displayed. The number “3” is displayed. The number “8” is displayed. None of the above.
B
C
D
E

Task No.:		Point(s):	2	Two answers are correct.	Cat. No.
For a quick check an ohmmeter can be used for testing a semiconductor diode. Which of the following conclusions about the testing results is correct?
A	A good diode should have a large reverse resistance compared to the forward resistance. The reverse resistance of a good diode appears to be an open circuit. The reverse resistance of a good diode appears to be a short circuit. The forward resistance of a good diode appears to be an open circuit. The forward resistance of a good diode is approximately equal to the reverse resistance.
B
C
D
E

Task No.:		Point(s):	1	One answer is correct.	Cat. No.
In the relay circuit shown below, when the START switch S2 is closed, the control relay K1 is …
A	energized, and the red and green lights are both on. de-energized, the red light is off, and the green light is on. energized, the red light is off, and the green light is on. energized, the red light in on, and the green light is off. energized, and the red and green lights are both off.
B
C
D
E

Task No.:		Point(s):	1	One answer is correct.	Cat. No.
The figure, as shown below, illustrates a typical application of a …
A	level switch. limit switch. temperature switch. pressure switch. proximity switch.
B
C
D
E

10.

A		The voltage at terminal A with respect to terminal C is +10V. The voltage at terminal B with respect to ground (GND) is +2.5V. The voltage at terminal A with respect to ground (GND) C is +5V. The voltage at ground (GND) with respect to terminal C is -2.5V. The voltage at terminal C with respect to terminal D is -5V.
B
C
D
E

11.

Task No.:		Point(s):	2	Two answers are correct.	Cat. No.
The power supply section required to provide electrical power is shown below. Which waveform of the signals and the corresponding numbers are correct?
A	3 – 4: pulsating full-wave DC voltage 7 – 6: pulsating full-wave DC voltage that is smoothed by C1 8 – 6: AC voltage with sinusoidal waveform 4 – 5: pulsating half-wave DC voltage 8 – 6: constant DC voltage over a specified range of load current
B
C
D
E

12.

Task. No.:		Points:	1	One answer is correct.

If the cross section area A (in cm2) of the piston, the supplied air pressure pe (in Bar),
and the reset force of the spring FR (in N) are given, which of the following equations is correct to
determine the force F (in N) of extension of the single-acting cylinder shown below.

A
B
C
D
E

13.

Task. No.:		Points:	1	One answer is correct.

For the extension of the cylinder shown below, a force of F = 300 N is needed.
If the frictional force is 10 % of F, how high must the applied air pressure pe be to move the slide?

A		pe = 0.25 bar
B		pe = 4.5 bar
C		pe = 5.5 bar
D		pe = 6.5 bar
E		pe = 9.7 bar

14.

Task. No.:		Points:	1	One answer is correct.

Which of the following statements about advantages and disadvantages of pneumatics is correct?

A			A
B			B
C			C
D			D
E			E
	A	Constant speed of the piston rod is possible.		Pressurized air is temperature sensitive.
	B	Pressurized air can be transported by air hoses.		The cylinder forces can not be adjusted continuously.
	C	High speed motion with pneumatic drives can be achieved.		Pneumatically actuated tools are not overload protected.
	D	Compressed air can escape without noise.		Compressors need a high noise protection.
	E	Compressed air can be stored in an air reservoir (accumulator).		Leakages cause an increase in energy costs.

15.

Task. No.:		Points:	1	One answer is correct.

Which of the following components are parts of an air service unit?

A		Cooler, filter, accumulator, pressure regulating valve
B		Manometer, filter, lubricator, vacuum generator
C		Pressure regulating valve, filter, cooler, pressure sensor
D		Filter, accumulator, manometer, lubricator
E		Filter, pressure regulating valve, lubricator

16.

Task. No.:		Points:	1	One answer is correct.

What is the use of the cushioning of a double-acting cylinder?

A		It protects the cylinder against excessively high air pressure.
B		It reduces the noise of the escaped air.
C		It prevents a hard striking of the piston at the end positions.
D		It holds the piston in position.
E		It controls the speed motion of the cylinder during extension.

17.

Task. No.:		Points:	1	One answer is correct.

A pneumatic valve is defined as a 5/2 - way valve. What does the number 5 mean in this definition?

A		The valve has a port for the exhaust.
B		The valve has 5 switching positions.
C		The valve has a neutral position and 4 other switching positions.
D		The valve has 5 ports.
E		The valve has 5 ports for work conductions.

18.

Task. No.:		Points:	1	One answer is correct.

Which component is represented symbolically?

A		3/2- way valve
B		5/2- way valve
C		4/2- way valve
D		5/3-way valve
E		Quick exhaust valve

19.

Task. No.:		Points:	1	One answer is correct.

How can the piston speed of cylinder 1A be greater during retraction than it is in
extension for the control system shown below?

A		By installation of a quick exhaust valve between valve 1V1 and 1V2
B		By installation of a silencer in valve 1V1
C		By installation of a flow control valve instead of the one-way flow control valve 1V3
D		By installation of a air reservoir between valve 1V3 and cylinder 1A
E		By installation of a quick exhaust valve instead of the one-way flow control valve 1V2

20.

Task. No.:		Points:	1	Two answers are correct.

Which statements about an electropneumatic control system are correct?
In the event of failure of the electrical power supply or a wire break …

A		… a double solenoid valve moves to the neutral position.
B		… a double solenoid valve position is unchanged.
C		… a spring-return valve combined with a dominant "ON" latching circuit moves to the neutral position.
D		… a spring-return valve combined with a dominant "OFF" latching circuit moves to the neutral position.
E		… a spring-return valve is ever actuated.

21.

Task. No.:		Points:	1	One answer is correct.

A simplified displacement step diagram is shown below. Which of the following statements
about the operation of the control system is correct?

A		While cylinder 2A advances, cylinder C1 remains in the actuated position.
B		Cylinder 2A advances after cylinder 1A has reached its retracted end position.
C		Cylinder 2A extends. When the forward end position is reached, the piston rod returns automatically.
D		The solenoid coil of 1V1 is energized as long as cylinder 1A advances and retracts.
E		Cylinder 1A retracts as soon as valve 2V1 is actuated.

22.

Task No.:		Point(s):	2	Two answers are correct.	Cat. No.
Which of the following statements about the gear assembly, as shown below, are correct?
A	The gear assembly exerts thrust (axial) forces. The pictured gears are used to increase operational noise. The rotation speed of the upper shaft is smaller than the rotation speed of the lower shaft The torque of the upper shaft is higher than the torque of the lower shaft. The module of both gears has to be the same.
B
C
D
E

23.

Task No.:	2	Point(s):	1	Only one answer is correct	Cat. No.:

How could you change the direction of rotation for an asynchronous machine (ASM) with squirrel cage?

A		Use secondary shaft on opposite side.
B		Exchange three terminals with each other.
C		Exchange two terminals with each other
D		Possible only with mechanical solutions (gear box and clutch).
E		Apply negative voltage to the terminals.

24.

Task No.:	4	Point(s):	2	More than one answer may be correct	Cat. No.:

An electrical DC machine gets too hot during operation. What could be the cause?

A		There is malfunction in the cooling system.
B		The load increased.
C		The supply voltage broke down.
D		The load decreased.
E		The brushes broke and have to be maintained.

25.

Task No.:	6	Point(s):	2	More than one answer may be correct	Cat. No.:

The ideal rotating magnetic field in the stator of a three-phase machine is deformed by:

A		High no-load speed.
B		Non-symmetrical stator windings.
C		Wrong direction of rotation.
D		Non-ideal net situation.
E		Alternating voltages and currents.

26.

Task No.:	8	Point(s):	2	More than one answer may be correct	Cat. No.:

A frequency inverter has a malfunction: one low-side switch is broken and as a result always opens.
Result for the driven asynchronous machine:

A		Half of the speed.
B		More torque ripple and more noise.
C		Less maximum torque.
D		Much less no-load speed.
E		The maximum torque will increase and possibly break the machine.

27.

Task No.:	10	Point(s):	1	Only one answer is correct	Cat. No.:

Which of the following rolling contact bearings are able to absorb thrust forces at least from one side?

A		Bearing b and e.
B		Bearing a, c and d.
C		Bearing a and d.
D		All bearings.
E		None of the answers given.

28.

Task. No.:		Points:	1	One answer is correct.

The basic function of a PLC is to ...
A		... amplify various weak signal sources.
B		... control the speed of motors.
C		... accept inputs, make logical decisions, and send outputs.
D		... control a high voltage output with a low voltage input.
E		... convert nonelectrical quantities into electrical voltage.

29.

Task. No.:		Points:	1	One answer is correct.

Field devices refer to ...

A		... input devices only.
B		... output devices only.
C		... load devices only.
D		... power devices only.
E		... all kind of sensors and actuators that are physically wired to PLC input/output modules.

30.

Task. No.:		Points:	1	One answer is correct.

The symbol shown below in a ladder diagram represents a(n) ...

A		... set of normally open contacts.
B		... imaginary coil that, when energized, will activate an digital output contact.
C		... a capacitor.
D		... is always a logic 0.
E		... is always a logic 1.

31.

Task. No.:		Points:	1	One answer is correct.

A device used to convert a binary number to a 7-segment display format is …

A		... a decoder
B		... a comparator
C		... a multiplexer
D		... a de-multiplexer
E		... an analog to digital converter

32.

Task. No.:		Points:	1	One answer is correct.

The binary number 1010 0111 1100 0101 can be written in hexadecimal as …

A		A7D5
B		A7C5
C		B7C3
D		B7E3
E		C7C5

33.

Task. No.:		Points:	1	One answer is correct.

The conversion of the decimal number 156 to 8421 BCD is…

A		0000 1001 1100
B		0001 0101 0110
C		0001 0000 1100
D		0000 0101 0110
E		0110 0101 0001

34.

Task. No.:		Points:	2	Two answers are correct.

Which of the following statements about a NAND gate are correct?

A		If all inputs are 1, the output will be 1.
B		If all inputs are 0, the output will be 0.
C		If all inputs are 0, the output will be 1.
D		If one or more inputs are 0, the output is 1.
E		NAND gates can have maximum 4 inputs.

35.

Task. No.:		Points:	1	One answer is correct.

A system contains two identical circuits operating in parallel as shown below.
As long as both are operating properly, the outputs of both circuits are always the same.
If one of the circuits fails, the outputs will be at opposite levels. To indicate the failure,
the outputs of the circuits are connected to the inputs of …

A		…a NOR gate.
B		…an OR gate.
C		…an XOR gate.
D		…an XNOR gate.
E		…a NAND gate.

36.

Task. No.:		Points:	1	One answer is correct.

Which of the following input combinations will definitely result in an output?

A		A AND B AND C
B		A AND NOT B AND NOT C
C		NOT C AND D
D		C AND NOT D
E		C AND D

37.

Task. No.:		Points:	1	One answer is correct.

Branch instructions are used to create:

A		series paths.
B		parallel paths.
C		a series of energized output conditions.
D		parallel connection of networks.
E		none of the above.

38.

Task. No.:		Points:	1	One answer is correct.

The Central Processing Unit (CPU) ...

A		... accepts inputs, makes decisions provided by the program, and sets outputs.
B		... accepts outputs. makes the decision provided by the program, and sets inputs.
C		... serves only to store the program in memory.
D		... understands only ladder logic.
E		... reads all inputs and outputs and makes decisions provided by the program.

39.

Task. No.:		Points:	1	One answer is correct.

Which of the following counter is available in STEP 7?

A		Up/Up counter
B		Up/Down counter
C		Retentive Down counter
D		Reset counter
E		Incremental counter

40.

Task. No.:		Points:	1	One answer is correct.

The move instruction copies data from …

A		... an integer byte to a floating byte.
B		... a floating byte to an integer byte.
C		... a destination byte to a source byte.
D		... a source byte to a destination byte.
E		... a double byte to a source byte.

41.

Task. No.:		Points:	1	One answer is correct.

The maximum number of outputs allowed per network in a Step 7 program is ...

A		... one.
B		... four.
C		... eight.
D		... 16.
E		... limited only by the memory size.

42.

Task. No.:		Points:	1	One answer is correct.

Parallel connections of a ladder logic program are typically called …

A		... rungs.
B		... branchs.
C		... loops.
D		... inputs.
E		... outputs.

43.

Task. No.:		Points:	1	One answer is correct.

What kind of signal varies continuously?

A		analog signal
B		variable signal
C		digital signal
D		discrete signal
E		permanent signal

44.

Task. No.:		Points:	1	One answer is correct.

The following digital system controls the number of work pieces going into a carton. The
preset number of 86 is entered on the keypad and also appears on the 7-segment display.
What is the specified content of register A and the data on 8-bit input B of the comparator
when the carton is full?

A		Register A: 1000 0110 Comparator input B: 0101 0110
B		Register A: 1000 0110 Comparator input B: 0110 1000
C		Register A: 0110 1000 Comparator input B: 0101 0110
D		Register A: 1000 0110 Comparator input B: 1000 0110
E		Register A: 0101 0110 Comparator input B: 0101 0110

A sensor at the bottom of the funnel neck detects each work piece that passes and produces an electrical pulse. The 8-bit binary counter contains the binary representation of the number of work pieces in the carton. The binary count is transferred to the 8-bit input B of the comparator. When the number in the counter reaches the preset number, the A=B output of the comparator goes HIGH, indicating that the carton is full.

45.

Task. No.: Points: 1 Only one answer is correct.
A S7-300/400 timer with a time base of 100 ms can count to a maximum value of seconds?

46.

Task. No. Points: 1 Only one answer is correct.
Which of the following statement is not correct?

a.	The CPU copies automatically the relevant program parts from the load memory into the work memory.	d.	Instead of the integrated bus systems at S7-400 racks, the S7-300 system has a pluggable backplane bus.
b.	In the S7-300 system, the CPU and 8 additional modules can be put on one rack.	e.	The bit-memory, the process-image input table and the accumulator 1 are parts of the system memory.
c.	There are not more than 4 extension racks possible.

47.

48.

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51.

52.

53.

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60.