Objective Questions on Control Panel Wiring for Electrician Trade
| Sr. No. | Questions with options |
| 1 | Which supply indicates by the color of conductor exhibited on Red, Blue and Black?
(a) Supply DC 3 wire system (b) Single phase AC system (c) Supply AC system 3 phase (d) Apparatus AC system 3 phase Ans- (a) |
| 2 | Which cable ties are used to bunch the wires?
(a) Silk ties (b) P.V.C ties (c) Nylon ties (d) Cotton ties Ans –(c) |
| 3 | Which device is avoided in the panel board assembly?
(a) Sensors (b) Indicating lamp (c) Isolating switch (d) Push button switch Ans –(a) |
| 4 | Which device protects from overload and short circuit in a panel board?
(a) Isolating switch (b) Time delay relay (c) Thermal overload relay (d) Miniature circuit breaker Ans – (d) |
| 5 | Which switch with an actuator is operated by the motion of a machine or part of an object?
(a) Limit switch (b) Toggle switch (c) Isolating switch (d) Push button switch Ans –(a) |
| 6 | Which switch is operated at OFF load condition?
(a) Limit switch (b) Isolating switch (c) Two way switch (d) Push button switch Ans – (b) |
| 7 | What is the reason for providing two separate earthing in panel board?
(a) Panel board is made in metal box (b) Control the stray field in the panel (c) Reduce the voltage drop in panel board (d) Ensure one earthing in case of other failure Ans-(d) |
| 8 | Which circuit, the limit switches are used?
(a) Lift circuits (b) Street lighting (c) Motor control circuits (d) Domestic power circuits Ans – (a) |
| 9 | How the control circuit voltage and power in a contactor are to be selected?
(a) As per rated current (b) As per supply voltage (c) As per no volt coil rating (d) As per the type of supply Ans – (c) |
| 10 | What is the criteria to select the contactor?
(a) Type of supply (b) Type of load connected (c) Supply voltage and load (d) Place of use the contactor Ans – (c) |
| 11 | Which accessory is used to mount MCB, OLR in the panel board without using screws?
(a) DIN Rail (b) G. channel (c) Grommets (d) PVC channel Ans – (a) |
| 12 | Which type of device protects motors from over heating and over loading in a panel board?
(a) Rectifier (b) Limit switch (c) Thermal relay (d) Electro mechanical relay Ans – (c) |
| 13 | What is the use of ‘G’ channels in control panel?
(a) For fixing relays (b) For fixing contactors (c) For fixing instruments (d) For fixing terminal connectors Ans – (d) |
| 14 | What is the function of limit switch in control panel wiring?
(a) Controls machine from over heat (b) Controls machine from over speed (c) Controls machine from over loading (d) Controls distance movement of any machine Ans – (d) |
| 15 | Which is the standard duty cycle code of the contactor for starting and stopping the AC resistive and inductive load?
(a) AC1 (b) AC2 (c) AC3 (d) AC4 Ans – (b) |
| 16 | Why control panels are provided with control transformer?
(a) To maintain rated voltage to load (b) To operate the auxiliary circuits (c) To maintain rated main supply voltage (d) To supply reduced voltage to power circuit Ans – (b) |
| 17 | What happens, if time delay relay of a auto star delta starter still in closed condition after starting?
(a) Starts and stop (b) Runs normally (c) Runs in star only (d) Runs in delta only Ans – (d) |
| 18 | What is the use of PVC channel in a control panel wiring?
(a) Mounting MCB (b) Mounting relays (c) Path way for electrical wiring and protection (d) Mounting double deck terminal contactor Ans – (c) |
| 19 | What is the purpose of the thermal over load relay in control panel?
(a) Switching ON/OFF the circuit (b) Protect the circuit from earth fault (c) Control the circuit based on time delay (d) Protect the motor from over heating and over loading Ans – (d) |
| 20 | Why sequential control of motors is required in an industrial application?
(a) To share more loads (b) To reduce power consumption (c) To minimize the operating cost (d) To increase the accuracy of operation Ans – (d) |
| Published On – 10th June 2022 | |
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