31. In batten wiring the cables are carried on seasoned teak wood perfectly straight and a well-varnished teak wood batten of a thickness not less than?
1 cm
3 cm
2 cm
4 cm
Answer.1. 1 cm
In the batten system of wiring TRS or PVCwires are run on well seasoned straight teak wood battens well varnished on four sides and of not less than 10 mm (1 cm) finished thickness, the width of which is such as to suit the total width of cables laid on the batten.
32. In an electric line, a switch is connected to which of the following wire?
Earth
Phase
Neutral
Not connected
Answer.2. Phase
Explanation:-
Different electrical loads are required to be switched in and switched off quite frequently. We use a switch to make and break the electrical connection to a load. This could be achieved by inserting a switch anywhere in the circuit. Switches must be connected in the circuit of a live wire so that the supply is dead when the switch is in the off position. If the Switch is provided in the neutral, there is a potential between the live wire and earth, even with the switch in the off position. This would cause a shock to the person repairing the lighting points with the switch in the off position. Switches for domestic lighting are standardized at 5 and 15-ampere capacity.
The switches for domestic installation have been standardized at 5A capacity for lighting circuits (such as electric lamps, fans, mobile chargers, etc.) and at 15A capacity for power circuits (such as microwave oven, washing machine, room heater, geyser, air-conditioner, etc.
33. Which of the following factor affecting the choice of wiring?
Durability
Appearance
Cost
All of the above
Answer.4. All of the above
Explanation:-
Factors Affecting the Choice of Wiring
(i) Durability: The type of wiring selected should conform to standard specifications so that it is durable, i.e., without being affected by the weather conditions, fumes, etc.
(ii) Safety: The wiring must provide safety against leakage, shock, and fire hazards for the operating personnel.
(iii) Appearance: Electrical wiring should give an artistic appeal to the interiors.
(iv) Cost: Electrical wiring should not be expensive and the maintenance cost should be minimum.
(v) Accessibility: The switches and plug points provided should be easily accessible. There must be provision for further extension of the wiring system, if necessary.
(vi) Mechanical Safety: The wiring must be protected against any mechanical damage.
34. What is the domestic wiring electrical layout?
A list or a plan of a building providing the first location of different points
The list of type of wiring.
The list of all the electrical components along with their prices.
Only i
Only ii
i, ii and iii
None of these
Answer.3. i, ii and iii
While planning the electrical installation for a residential building, the first location of different points (fan points, light points, etc.) should be done. Then we should select the type of wiring (i.e., conduit wiring or CTS or cleat wiring, etc.,) depending upon the safety, cost, life, appearance, nature of the load, etc. All runs of wiring and the exact positions of outlets, switch boxes, etc., should be marked. Generally, a single-phase system is used for residential buildings.
35. What is the domestic wiring electrical layout?
A list or a plan of a building providing information on a number of points in each room.
The list of all the electrical components required for a particular room.
The list of all the electrical components along with their prices.
Only i
Only ii
Both ii and iii
None of these
Answer.1. only i
Electricity Schedule List or plan of the building containing information about the number of points in each room. The material used in electrical wiring must bear the I.S.I mark. The circuit of light and fan in the home is the same, but the power circuit should be different. The circuit arrangement should be such that at least one additional circuit can be provided for future expansion. Hence the list or plan of the building should contain information about the number of points in each room.
Preparing an electrical schedule helps in determining the amount of power required for an installation. This information is then used by electrical engineers to properly size conductors, conduits and determine the proper load and other protection and control systems.
35. For what voltage levels are the screwed conduit circuits used?
Less than 259V
Between 250 V- 600 V
Above 600V
None of these
Answer.2. Between 250 V- 600 V
Explanation:-
Screwed conduit is produced as standard finished in black enamel for general purposes, and galvanized for use in damp situations, although special finishes may also be applied.
A screwed conduit system must be mechanically and electrically continuous across all joints so that the electrical resistance of the conduit, together with the resistance of the earthing lead, measured from the earth electrode to any position in the conduit system shall be sufficiently low so that the earth fault current operates the protective device.
The screwed conduit circuits are used to protect the electrical wiring. It is used for the voltage levels in between 250 V to 600 V
36. Which of the following is the testing method of wiring?
Polarity test
Short circuit test
Continuity test
All of the above
Answer.4. All of the above
Explanation:-
Testing method of wiring – before giving supply to new wiring. It should be tested as per the provision of the Indian Electricity Rule. Now wiring should be tested by megger to ensure that there is no open circuit, short circuit or leakage. Following tests are done before giving supply.
i) Insulation test between earth and wiring.
ii) Insulation test between conductors.
iii) Polarity test
iv) Short circuit test
v) Circuit continuity test or open circuit test.
vi) Earth continuity test.
37. Which type of lamp holder from the following is fitted directly on the wooden board?
Pendent holder
Angle holder
Bracket holder
Batten holder
Answer.4. Batten holder
A lamp holder is used to support the lamp and also to connect it electrically to the supply system.
Batten Holder: This type of lamp holder is fitted directly on the wooden board, which itself is fixed on the wall. The lamp is then supported in the batten holder.
38. The type of lamp holder used for the direct light requirment is?
Pendent holder
Angle holder
Bracket holder
Batten holder
Answer.3. Bracket holder
Explanation:-
Bracket Holders: These are used where direct light is needed in the room. These are also used in table lamps. Brackets used with such types of holders are made of brass material.
39. Which of the following wiring system is not used in domestic wiring?
Tree system
Distribution system
Branch system
All of the above
Answer.1. Tree system
Explanation:-
Tree System – This is commonly called a Tree System because branch lines are tapped from the mainline in the shape of that of the branch line (which is thinner) according to loads of branches and main line. This system is not suitable for domestics wiring. This system is commonly used in ships.
Distribution System – In this system supply is first given to main switch then to one or more distribution boards after the main switch. From distribution board supply is given to different branch circuits. Branch circuits are joined through a separates fuse or MCB. Each branch circuit can be operated separately. There is no need of tapping wire.
40. _______ is used in electrical installation to join conductors and provide a path for the conductor.
Path Box
Route Box
Junction Box
Conduit Box
Answer.3. Junction Box
Explanation:-
Junction Box Junction boxes are used in electrical installation to join some conductors and provide different paths for different conductors. If the looping system is used, junction boxes are not needed.
