Question 1 of 37

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

Limit switch

Push button switch

Isolating switch

Toggle switch

Question 1 of 37

Question 2 of 37

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

No voltage exist in reverse contactor

Fault in forward contactor

No volt coil is not energized

Due to interlock in reverse contactor

Question 2 of 37

Question 3 of 37

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

Switching ON/OFF the circuit

Control the circuit based on time delay

Protect the motor from over heating and loading

Protect the circuit from earth fault

Question 3 of 37

Question 4 of 37

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

Starting and stopping of shunt motor

Starting and stopping with inching and braking

Resistive loads except motor loads

Starting and stopping of series motor

Question 4 of 37

Question 5 of 37

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

AC₁

AC₄

AC₂

AC ₃

Question 5 of 37

Question 6 of 37

6. Which switch is operated at OFF load condition?

Isolating switch

Limit switch

Push button switch

Two way switch

Question 6 of 37

Question 7 of 37

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

Rectifier

Electro mechanical relay

Thermal relay

Limit switch

Question 7 of 37

Question 8 of 37

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

Cable binding straps and button

Lugs and thimbles

Sleeves

Wire ferrules

Question 8 of 37

Question 9 of 37

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

PVC channel

DIN Rail

G. channel

Grommets

Question 9 of 37

Question 10 of 37

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

By providing nylon cable ties

By using Grommets

By using cable binding straps

By using sleeve

Question 10 of 37

Question 11 of 37

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

Nylon cable ties

Wire ferrules

Cable binding strap

Wire sleeves

Question 11 of 37

Question 12 of 37

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

Timer

Contactor

Control transformer

Relays

Question 12 of 37

Question 13 of 37

13. What is the criteria to select the contactor?

Type of load connected

Type of supply

Supply voltage and load

Place of use the contactor

Question 13 of 37

Question 14 of 37

14. Why are control panels provided with control transformer?

To maintain rated main supply voltage

To maintain rated voltage to load

To supply reduced voltage to power circuit

To operate the auxiliary circuits

Question 14 of 37

Question 15 of 37

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

Silver

Bronze

Copper

Brass

Question 15 of 37

Question 16 of 37

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

Main→Timer→Delta→Star

Star→Timer→Main→Delta

Main→Star→Delta→Timer

Star→Main→Timer→Delta

Question 16 of 37

Question 17 of 37

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

Push button switch

Sensors

Indicating lamp

Isolating switch

Question 17 of 37

Question 18 of 37

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

For fixing relays

For fixing terminal connectors

For fixing contactors

For fixing instruments

Question 18 of 37

Question 19 of 37

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

Silk ties

Nylon ties

P.V.C ties

Cotton ties

Question 19 of 37

Question 20 of 37

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

Install the high powered circuit accessories

Mounting the control accessories without screws

Mounting the double deck terminal connectors

It provides a pathway for electrical wiring

Question 20 of 37

Question 21 of 37

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

As per rated current

As per no volt coil rating

As per the type of supply

As per supply voltage

Question 21 of 37

Question 22 of 37

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

Controls machine from over speed

Controls distance movement of any machine

Controls machine from over loading

Controls machine from over heat

Question 22 of 37

Question 23 of 37

23. 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

Outside dimensions and swing area of cabinet door

Inside area and number of indicating lights in front panel

Question 23 of 37

Question 24 of 37

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

Runs in delta only

Starts and stop

Runs normally

Runs in star only

Question 24 of 37

Question 25 of 37

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

DIN rails

Race ways

Grommets

G channel

Question 25 of 37

Question 26 of 37

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

Reduce the voltage drop in panel board

Panel board is made in metal box

Ensure one earthing in case of other failure

Control the stray field in the panel

Question 26 of 37

Question 27 of 37

27. Which circuit uses limit switches?

Domestic power circuits

Motor control circuits

Street lighting

Lift circuits

Question 27 of 37

Question 28 of 37

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

To minimize the operating cost

To increase the accuracy of operation

To share more loads

To reduce power consumption

Question 28 of 37

Question 29 of 37

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

Miniature circuit breaker

Time delay relay

Thermal overload relay

Isolating switch

Question 29 of 37

Question 30 of 37

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

Auxiliary contact

Start button

Stop button

Main contact

Question 30 of 37

Question 31 of 37

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

Over load relay trip

Stop button

Contactor

No volt coil

Question 31 of 37

Question 32 of 37

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

To supply the power to the auxiliary circuits

To maintain constant terminal voltage

To control the supply voltage to the contactor

To protect the control elements from over voltage fault

Question 32 of 37

Question 33 of 37

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

Grommet

Lugs

Terminal connector

Thimble

Question 33 of 37

Question 34 of 37

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

To increase the current carrying capacity

To reduce heat

To increase the insulation resistance

To reduce the radio interference

Question 34 of 37

Question 35 of 37

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

Apparatus AC system 3 phase

Supply AC system 3 phase

Single phase AC system

Supply DC 3 wire system

Question 35 of 37

Question 36 of 37

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

By using bimetallic strip to change the position

By mechanical settings

By operating electromagnet to change the position

By manual operation

Question 36 of 37

Question 37 of 37

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

Mounting relays

Mounting double deck terminal contactor

Mounting MCB

Pathway for electrical wiring and protection

Question 37 of 37