Plc vs scada

21. Which among these components connect to physical equipments of distributed control system?

1. RTU
2. Central room computer
3. Communication infrastructure
4. None of the above

Correct answer: Central room computer

22. The function of data acquisition begins at

1. Communication infrastructure
2. Central room computer
3. None of the above

Correct answer: Communication infrastructure

23.In a SCADA system , the operator interface is driven by

1. Communication infrastructure
2. PLC
3. Alarm
4. RTU

            Correct answer: RTU

24.In a SCADA system the host computer performs

1. Data acquisition functions;’
2. Computational tasks
3. Communication
4. All of these
5. Correct answer: All of these

      25. Information display is achieved in the form of

1. Limited graphics
2. CRT color pages
3. Both (a) and (b)
4. None of the above

Correct answer: Both (a) and (b)

      26. During supervisory control which of the following methods is employed for verification

1. Set point control
2. Report by exception
3. Check before operate
4. Sequence of events acquisition

Correct answer: Set point control

      27. Alarm processing refers to which of the following

1. Acquiring data from the field RTU
2. Set point control of the RTU
3. Altering the operator for unscheduled events
4. Retrieving real time data

Correct answer: Altering the operator for unscheduled events
     
     
      28. Accurate record keeping is essential for

1. Legal requirements
2. Accounting purpose
3. Forecasting purpose
4. All of the above

Correct answer: All of the above

 

29. Capturing and recording unscheduled events with a time resolution of few milliseconds is referred to as,

1. Information storage
2. Supervisory control
3. Data calculation
4. None of the above

Correct answer: Supervisory control

30.The typical time resolution of events captured during a SOE operation

1. 5ms
2. 10ms
3. 2ms
4. 3ms

Correct answer:5ms

 

               31. Calculation of average and integration wrt to time will be a part of

1. Information display
2. Sequence of events acquisition
3. Data calculation
4. Alarm processing

Correct answer: Data calculation

                32. Determination of whether a transmission line is energized or not is a good example of

1. Sequence of events
2. Information display
3. Combinational processing
4. Data acquisition

Correct answer: Data acquisition

 

                33. The highly reliable information storage that a SCADA system offers can be used for

1. Distribution automation
2. Minimizing cost
3. Centralized control
4. Forecasting

Correct answer: Distribution automation

 

               34. Which of the following protocol offers a byte stream service

1. UDP
2. TCP
3. RPC
4. SNMP

Correct answer: TCP

            35. Majority of LAN devices employ SNMP due to

1. It is cheap
2. It is simple
3. It has low resource consumption
4. Both (b) and (c)

Correct answer: Both (b) and (c)

 

36.  A signal contains components with frequencies up to 10 kHz, although no      useful information is contained at frequencies above 6 kHz. What is the minimum frequency at which the signal should be sampled?
a)6 kHz b)12kHz c)14.4kHz d)20 kHz Correctanswer : 14.4kHz

38. What is the resolution of a 12-bit data converter?

1. 0.00024%
2. 0.0041%
3. 0.024%
4. 0.41

Correct answer: 0.024%

39. What would be a typical settling time for a general-purpose 8-bit ADC?

a)1 ns to 10 ns
b)100 ns to 1 s
c)10 s to 100 s
d) 100 s to 1 s
Correct answer: 100 ns to 1 s

40. What is meant by the droop of a sample and hold gate?

1. The voltage by which the input quantity is lowered during sampling.
2. The voltage difference between the output voltage and the actual voltage being sampled.
3. The time taken to take a sample.
4. The rate of decay of the output voltage.

Correct answer: The rate of decay of the output voltage.

41. An analogue multiplexer is a form of electrically controlled switch, based on the use of analogue switches.

1. True
2. False

Correct answer: True

42. What is the primary function of the sample and hold gates in the following arrangement.

1. To prevent the ADC from distorting the input signals.
2. To allow all the inputs to be sampled simultaneously.
3. To block unwanted input signals.                 
4. To buffer the input signals.

Correct answer: To allow all the inputs to be sampled simultaneously.

43. What is meant by a single-chip data acquisition system?

1. A single integrated circuit containing all the elements of a data acquisition system.
2. A single integrated circuit containing an ADC and a multiplexer.
3. A single integrated circuit containing a DAC and a demultiplexer.
4. A single integrated circuit containing an ADC and a DAC

Correct answer: A single integrated circuit containing an ADC and a multiplexer.

 

44. What is the primary function of the sample and hold gates in the following arrangement.

 a)To hold the outputs constant between updates of the outputs.
b)To buffer the output signals.
c)To allow the outputs to be updated simultaneously.
d)To prevent variations in the load from affecting the output voltage.

Correct answer: To hold the outputs constant between updates of the outputs.

45.A 16-input multiplexer is to be used to perform parallel-to-serial data conversion. Which of the following counters would be required to provide the data select inputs? MOD 8 MOD 16 MOD 4 MOD 2 answer : MOD 16

 

46.Multiplexing of digital signals is usually required when:

1. moving data internally within a microprocessor.
2. moving data between memory and storage registers in a microprocessor.
3. moving data over long distance transmission lines.
4. moving data internally within a microprocessor or between memory and storage registers.

Correct answer: moving data over long distance transmission lines.

   

47.One can safely state that the output lines for a demultiplexer are under the direct control of the: input data select lines the internal AND gates. the internal OR gate. Input data line. Correct answer: input data select lines.
48.What is the purpose of a decoder's inputs? To allow the decoder to respond to the inputs to activate the correct output gate. To disable the decoder outputs so that all outputs will be inactive. To disable the inputs and activate all outputs.   Correct answer: To allow the decoder to respond to the inputs to activate the correct output gate, and to disable the inputs and activate all outputs. 49. Which statement below best describes the function of a decoder? A decoder will convert a decimal number into the proper binary equivalent. A decoder will convert a binary number into a specific output representing a particular character or digit Decoders are used to prevent improper operation of digital systems. Correct answer : To allow the decoder to respond to the inputs to activate the correct output gate, and to disable the inputs and activate all outputs. 50. The IEEE/ANSI symbol for a decoder has the internal designation bcd/dec. This means the decoder is a: decimal-to-BCD decoder with ten inputs and four outputs. BCD-to-decimal decoder with ten inputs and four outputs. decimal-to-BCD decoder with four inputs and ten outputs. BCD-to-decimal decoder with four inputs and ten outputs.

 

Correct answer : BCD-to-decimal decoder with four inputs and ten outputs