Question 1 of 37

1. What is the use of PVC channel in a control panel wiring?

Pathway for electrical wiring and protection

Mounting relays

Mounting double deck terminal contactor

Mounting MCB

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Question 2 of 37

2. Which device is avoided in the panel board assembly?

Indicating lamp

Isolating switch

Sensors

Push button switch

Question 2 of 37

Question 3 of 37

3. What is the purpose of thermal overload relay in control panel?

Control the circuit based on time delay

Protect the motor from over heating and loading

Switching ON/OFF the circuit

Protect the circuit from earth fault

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Question 4 of 37

4. What is the name of the device marked as 'X' in the circuit?

No volt coil

Over load relay trip

Contactor

Stop button

Question 4 of 37

Question 5 of 37

5. Why is sequential control of motors required in industrial applications?

To increase the accuracy of operation

To minimize the operating cost

To reduce power consumption

To share more loads

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Question 6 of 37

6. Which cable ties are used to bunch the wires?

Cotton ties

Nylon ties

P.V.C ties

Silk ties

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Question 7 of 37

7. Which device controls the operations in sequential control systems?

Timer

Relays

Control transformer

Contactor

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Question 8 of 37

8. What is the name of the accessory used in control panel wiring?

Lugs

Thimble

Terminal connector

Grommet

Question 8 of 37

Question 9 of 37

9. Which accessory is used to mount MCB, OLR in the panel board without using screws?

Grommets

DIN Rail

PVC channel

G. channel

Question 9 of 37

Question 10 of 37

10. Why power and control wirings run in separate race ways?

To reduce the radio interference

To increase the insulation resistance

To reduce heat

To increase the current carrying capacity

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Question 11 of 37

11. Which material is used to make open frame bimetallic adjustable thermostat contacts?

Bronze

Copper

Silver

Brass

Question 11 of 37

Question 12 of 37

12. What happens if time delay relay of an auto star-delta starter remains in closed condition after starting?

Starts and stop

Runs in delta only

Runs in star only

Runs normally

Question 12 of 37

Question 13 of 37

13. Which is the correct sequence operation of contactors for operating automatic star-delta starter?

Star→Timer→Main→Delta

Main→Timer→Delta→Star

Star→Main→Timer→Delta

Main→Star→Delta→Timer

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Question 14 of 37

14. How should control circuit voltage and power in a contactor be selected?

As per no volt coil rating

As per the type of supply

As per rated current

As per supply voltage

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Question 15 of 37

15. Which DC load is represented by the DC4 standard duty cycle of contactors?

Resistive loads except motor loads

Starting and stopping of shunt motor

Starting and stopping with inching and braking

Starting and stopping of series motor

Question 15 of 37

Question 16 of 37

16. How to protect the cable from insects and rats into the panel?

By providing nylon cable ties

By using sleeve

By using cable binding straps

By using Grommets

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Question 17 of 37

17. What is the name of the wiring accessory used in control panel wiring?

Grommets

G channel

Race ways

DIN rails

Question 17 of 37

Question 18 of 37

18. What is the purpose of DIN-rail used in control panel wiring?

Mounting the double deck terminal connectors

Mounting the control accessories without screws

It provides a pathway for electrical wiring

Install the high powered circuit accessories

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Question 19 of 37

19. What is the criteria to select the contactor?

Place of use the contactor

Supply voltage and load

Type of supply

Type of load connected

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Question 20 of 37

20. What essential feature to be considered while designing a layout of control panel?

Proper type of protection and measuring system

Suitable method of labelling and cable harnessing

Inside area and number of indicating lights in front panel

Outside dimensions and swing area of cabinet door

Question 20 of 37

Question 21 of 37

21. Which switch with an actuator is operated by the motion of a machine or part of an object?

Limit switch

Toggle switch

Isolating switch

Push button switch

Question 21 of 37

Question 22 of 37

22. What is the function of limit switch in control panel wiring?

Controls distance movement of any machine

Controls machine from over speed

Controls machine from over heat

Controls machine from over loading

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Question 23 of 37

23. What is the reason for providing two separate Earthings in panel board?

Panel board is made in metal box

Control the stray field in the panel

Reduce the voltage drop in panel board

Ensure one earthing in case of other failure

Question 23 of 37

Question 24 of 37

24. Which switch is operated at OFF load condition?

Push button switch

Limit switch

Isolating switch

Two way switch

Question 24 of 37

Question 25 of 37

25. What is the purpose of control transformer used in control panel wiring?

To supply the power to the auxiliary circuits

To protect the control elements from over voltage fault

To control the supply voltage to the contactor

To maintain constant terminal voltage

Question 25 of 37

Question 26 of 37

26. Which device protects from overload and short circuit in a panel board?

Isolating switch

Thermal overload relay

Time delay relay

Miniature circuit breaker

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Question 27 of 37

27. What is the name of the device marked as 'X'?

Stop button

Start button

Main contact

Auxiliary contact

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Question 28 of 37

28. Which circuit uses limit switches?

Domestic power circuits

Street lighting

Motor control circuits

Lift circuits

Question 28 of 37

Question 29 of 37

29. Which device prevents flare out of stripped and stranded cables in the panel board?

Lugs and thimbles

Sleeves

Wire ferrules

Cable binding straps and button

Question 29 of 37

Question 30 of 37

30. What is the name of the accessory used in control panel wiring?

Wire sleeves

Wire ferrules

Cable binding strap

Nylon cable ties

Question 30 of 37

Question 31 of 37

31. What is the use of 'G' channels in control panel?

For fixing relays

For fixing instruments

For fixing terminal connectors

For fixing contactors

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Question 32 of 37

32. Which supply is indicated by the color of conductor exhibited on Red, Blue and Black?

Supply AC system 3 phase

Supply DC 3 wire system

Apparatus AC system 3 phase

Single phase AC system

Question 32 of 37

Question 33 of 37

33. Why are control panels provided with control transformer?

To maintain rated main supply voltage

To supply reduced voltage to power circuit

To operate the auxiliary circuits

To maintain rated voltage to load

Question 33 of 37

Question 34 of 37

34. Which type of device protects motors from over heating and over loading in a panel board?

Thermal relay

Electro mechanical relay

Rectifier

Limit switch

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Question 35 of 37

35. How are the contacts in a contactor engaged for working?

By manual operation

By operating electromagnet to change the position

By mechanical settings

By using bimetallic strip to change the position

Question 35 of 37

Question 36 of 37

36. Which is the standard duty cycle code of the contactor for starting and stopping the AC resistive and inductive load?

AC₄

AC₁

AC ₃

AC₂

Question 36 of 37

Question 37 of 37

37. Why the motor is not changing the direction, if reverse push button is pressed in forward and reverse control star delta starter?

No volt coil is not energized

No voltage exist in reverse contactor

Fault in forward contactor

Due to interlock in reverse contactor

Question 37 of 37