IE Rules MCQ Quiz - Objective Question with Answer for IE Rules - Download Free PDF
Last updated on Jun 10, 2025
Latest IE Rules MCQ Objective Questions
IE Rules Question 1:
What is the minimum clearance of HV Lines from ground across streets?
Answer (Detailed Solution Below)
IE Rules Question 1 Detailed Solution
Explanation:
Minimum Clearance of HV Lines from Ground Across Streets
Definition: High Voltage (HV) lines are power transmission lines designed to carry electrical energy over long distances at high voltages to minimize losses and ensure efficient power distribution. For safety and operational purposes, these lines need to maintain a minimum clearance from the ground, especially when crossing streets or public areas.
Correct Option Analysis:
The correct option is:
Option 3: 6 meters
The minimum clearance of HV lines from the ground across streets is mandated to be 6 meters as per electrical safety standards and regulations. This standard ensures the safety of pedestrians, vehicles, and infrastructure while preventing accidental contact with the transmission lines. The clearance height is carefully determined based on several factors, including the voltage level, environmental conditions, and expected traffic patterns in the area.
Reasons for Minimum Clearance:
- Safety of People and Vehicles: Adequate clearance prevents accidental contact with HV lines, which can lead to electrocution and fatal accidents.
- Protection Against Sag: HV lines tend to sag due to thermal expansion or heavy load. Maintaining a minimum clearance ensures the lines do not dip dangerously close to the ground or structures.
- Compliance with Regulations: Electrical safety standards, such as those outlined by the National Electrical Code (NEC) or local governing bodies, specify minimum clearance requirements to ensure public safety.
- Environmental Factors: Factors like wind, temperature changes, and natural disasters can affect the position of HV lines. The clearance ensures that even under adverse conditions, the lines remain safely above the ground.
Applications: These clearances are critical in urban planning, infrastructure development, and power grid design. They are particularly important when HV lines cross busy streets, highways, or densely populated areas.
Important Information
To further understand the analysis, let’s evaluate the other options:
Option 1: 3 meters
This option is incorrect because 3 meters is far too low a clearance for HV lines, especially when crossing streets. Such a clearance would pose a significant danger to vehicles, pedestrians, and infrastructure. It would also fail to comply with most electrical safety standards.
Option 2: 8 meters
This option exceeds the standard minimum clearance of 6 meters. While it provides additional safety, it is not the mandated minimum clearance. Installing HV lines at such a height might lead to unnecessary costs and structural complexities, especially in areas where 6 meters is deemed sufficient for safety.
Option 4: 5 meters
This option is incorrect because 5 meters does not meet the standard minimum clearance required for HV lines across streets. While it might be suitable for low-voltage lines or certain private installations, HV lines require a greater clearance due to their higher potential danger and sagging risks.
Option 5: Not Provided
This option does not specify any clearance value and thus cannot be considered correct. Standards and regulations require a definitive minimum clearance, which for HV lines is 6 meters across streets.
Conclusion:
The minimum clearance of HV lines from the ground across streets is a critical safety standard established to protect public safety and ensure the efficient operation of power transmission systems. The mandated clearance of 6 meters ensures adequate safety, compliance with regulations, and adaptability to environmental factors. While other options either fall short or exceed the standard, 6 meters strikes the right balance between safety, practicality, and cost-effectiveness.
IE Rules Question 2:
If a house must be installed with 8 power socket outlets, then the total number of power sub-circuits required is:
Answer (Detailed Solution Below)
IE Rules Question 2 Detailed Solution
Explanation
As per IEEE, a maximum number of 2 power socket outlets must be present in a single power sub-circuit.
1 power sub-circuits = 2 power socket outlets
So for 8 power socket outlets, 4 power sub-circuits are required.
IE Rules Question 3:
Which of the following is a sign of danger associated with overhead installations?
Answer (Detailed Solution Below)
IE Rules Question 3 Detailed Solution
Danger Notice:
Danger overhead Installations:
Flammable Material:
High Voltage Warning:
IE Rules Question 4:
For proper earthing, according to I.E. Rules, of power equipments -
Answer (Detailed Solution Below)
IE Rules Question 4 Detailed Solution
Double earthing system is used for earthing of power equipment.
Explanation:
According to Section-90 of IE Rules, two earthing must be provided to power equipment because:
- If there is one earth circuit and the current path gets broken then the enclosed body or equipment may attain live potential. Therefore, the second point must be provided in parallel to the first in order to divert the fault current through the second in case the first becomes in-operative.
- By connecting two earthing points in parallel, the equivalent resistance of the circuit becomes low. The low resistance of the circuit causes an easy flow of fault current to the earth.
IE Rules Question 5:
Fill in the blank(s) with the correct option:
According to IE rules, 1956, low voltage is where the voltage does not exceed _______.
Answer (Detailed Solution Below)
IE Rules Question 5 Detailed Solution
1. Definition of Voltage Class as per Rule 54 of Indian Electricity Rules,1956:
Voltage Class | Abbreviation | Max. Voltage under Normal Conditions |
Variations Allowed |
Low | LV | 250 V | -6% to +6% |
Medium | MV | 650 V | -6% to +6% |
High | HV | 33,000 V | -9% to + 6% |
Extra High | EHV | 33,000 V"}" style="text-align: center;">> 33,000 V | 12.5% to + 10% |
2. Definition of Voltage Class as per the National Electric Code (of India) 2011:
Low Voltage: The voltage which does not normally exceed 250 V
Medium Voltage: The voltage which normally exceeds 250 V but does not exceed 650 V
High Voltage: The voltage which normally exceeds 650 V (but less than 33 kV)
Extra-High Voltage: The voltage exceeding 33 kV under normal conditions.
Top IE Rules MCQ Objective Questions
Answer (Detailed Solution Below)
IE Rules Question 6 Detailed Solution
Download Solution PDFThe symbol of different Transformer is shown below:
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Three Winding Transformer |
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Current Transformer |
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Step Down Transformer |
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Step Up Transformer |
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Ferrite Core Transformer |
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Iron Core Transformer |
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Variable Transformer |
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Air-Core Transformer |
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Auto Transformer |
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If the wiring in a building as a 2.4-kW load, what will be the permissible insulation resistance to earth for a 240-V system of supply?
Answer (Detailed Solution Below)
IE Rules Question 7 Detailed Solution
Download Solution PDFConcept:
Full Load Current(IFL): A full load current is a maximum current that electrical equipment is designed to carry under rated conditions.
Leakage current(Ilek): A leakage current is an electric current in an unwanted conductive path under normal operating conditions.
Note: According to IE Rule 48 The maximum permissible value of leakage current should not be exceeded beyond the \(\frac{1}{{5000}} \)times of full load current.
Insulation Resistance(IR): An insulation resistance (IR) is the total resistance between any two points separated by electrical insulation.
It is given by,
\(IR = \frac{{Supply\;Voltage}}{{{I_{lekage}}}}\)
Note: IR of a cable is also given as:
\(IR = \frac{\rho }{{2\pi l}}{\log _e}\frac{{{r_2}}}{{{r_1}\;}}\)
Where ρ is the resistivity of cable on Ωm
l is the length of cable in the metre.
r1 is the radius of core in metre
r2 is the radius of cable in metre
Calculation:
Given, P = 2.4 kW, V = 240 V
IFL = 2400 / 240 = 10 A
According to IE Rule 48:
\({I_{lek}} = \frac{{{I_{FL}}}}{{5000}} = \frac{{10}}{{5000}} = 0.002\;A\)
∴\(IR = \frac{{supply\;voltage}}{{{I_{lekage}}}} = \frac{{240}}{{0.002}} = 120,000 = 0.12\;M{\rm{\Omega }}\)
Answer (Detailed Solution Below)
IE Rules Question 8 Detailed Solution
Download Solution PDFDifferent Type of Tower Design:
1. Three Phase Single circuit two ground wire Tower:
2. Three Phase Single circuit one ground wire Tower:
2. Double Three Phase Single circuit one ground wire Tower:
4. HVDC Bipolar Tower:
For specific wiring in a building, the full load current is 7.5 A. what will be the permissible insulation resistance to earth for a 240 V system of supply?
Answer (Detailed Solution Below)
IE Rules Question 9 Detailed Solution
Download Solution PDFConcept:
Full Load Current(IFL): A full load current is a maximum current that electrical equipment is designed to carry under rated conditions.
Leakage current(Ilek): A leakage current is an electric current in an unwanted conductive path under normal operating conditions.
Note: According to IE Rule 48 The maximum permissible value of leakage current should not be exceeded beyond the \(\frac{1}{{5000}} \)times of full load current.
Insulation Resistance(IR): An insulation resistance (IR) is the total resistance between any two points separated by electrical insulation.
It is given by,
\(IR = \frac{{Supply\;Voltage}}{{{I_{lekage}}}}\)
Note: IR of a cable is also given as:
\(IR = \frac{\rho }{{2\pi l}}{\log _e}\frac{{{r_2}}}{{{r_1}\;}}\)
Where ρ is the resistivity of cable on Ωm
l is the length of cable in the metre.
r1 is the radius of core in metre
r2 is the radius of cable in metre
Calculation:
Given, IFL = 7.5 A
According to IE Rule 48:
\({I_{lek}} = \frac{{{I_{FL}}}}{{5000}} = \frac{{7.5}}{{5000}} = 0.0015\;A\)
∴\(IR = \frac{{supply\;voltage}}{{{I_{lekage}}}} = \frac{{240}}{{0.0015}} = 160,\;000 = 0.16\;M{\rm{\Omega }}\)
According to the IS code, the colour of earth wire is usually:
Answer (Detailed Solution Below)
IE Rules Question 10 Detailed Solution
Download Solution PDF
Function |
Colour code |
Single-phase line |
Red/Brown |
Single-phase neutral |
Black/Blue |
Single-phase protective ground or earth |
Green |
Three-phase line 1 |
Red |
Three-phase line 2 |
Yellow |
Three-phase line 3 |
Blue |
Three-phase neutral |
Black |
Three-phase protective ground or earth |
Green (or) Greenish Yellow |
As per IE Rules, the terminal voltage must be within the ________ range, if the nominal voltage is 240 V.
Answer (Detailed Solution Below)
IE Rules Question 11 Detailed Solution
Download Solution PDFIndia Electricity Rule No. - 54
A supplier shall not permit the voltage at the point of commencement of supply to vary from the declared voltage.
a) In case of low & medium voltage, the variation not more than by 6%.
b) In case of High voltage by 6% in the higher side and 9% in lower side.
c) In case of extra high voltage by 10% in the higher side and 12.5% in lower side.
Calculation:
± 6 % of 240 V
\( ± \;\frac{6}{{100}} \times 240 = \; ± \;14.4\;V\)
Required voltage = 240 ± 14.4 V
Required voltage = 225.6 & 254.4 V
Therefore voltage should not drop below 225.6 V and should not exceed by 254.4 V.
So the correct range will be 228 V to 252 V.
Important Points
India Electricity Rule No. - 55
Variation in frequency of A.C supply should not be more than 3%.
As per IE regulations when service lines are installed elsewhere other than along or across any street, the conductor of line at any part shall have a height not less than a specified value. What is the value for 11 kV lines
Answer (Detailed Solution Below)
IE Rules Question 12 Detailed Solution
Download Solution PDFConcept:
Extra-high voltage lines 3.0 meters. In any case of a crossing referred to in sub-rule, whoever lays his line later in time, shall provide the clearance between his own line and the line which will be crossed in accordance with the provisions of said sub-rule: Provided that if the later entrant is the owner of the lower line and is not able to provide adequate clearance, he should bear the cost for modification of the upper line so as to comply with this rule.
The voltage level in kV | Ground clearances in meter |
Low/ medium/ HT Line up to 11kV, if bare conductor | 4.6 |
Low/ medium/ HT Line up to 11kV, if insulated conductor | 4.0 |
Above 11 kV line | 5.2 |
Above 33 kV line | 5.8 |
Which of the following IE rule gives importance to the restoration of persons suffering from electric shock?
Answer (Detailed Solution Below)
IE Rules Question 13 Detailed Solution
Download Solution PDFIE Rule 44: Instruction for the restoration of persons suffering from electric shock
IE Rule 46: Periodical Inspection and testing of consumer’s Installation
IE Rule 37: Supply to vehicles cranes etc.
IE Rule 38: Cables for portable or transportable apparatusAccording to BIS, the panel board and meter board are to be kept at a height of ________.
Answer (Detailed Solution Below)
IE Rules Question 14 Detailed Solution
Download Solution PDFIE Rules regarding internal domestic wiring
- The minimum size of the conductor used in domestic wiring not be less than 1/1.12 mm in copper or 1/1.40 mm in the aluminum wire.
- The casing will be run at a height of 3.0 meters from ground level.
- Light brackets should be fixed at a height of 2 to 2.5 meters above the ground level.
- The height at which the meter board, the main switchboard is to be fitted is 1.5 meters from ground level.
- A switch shall be installed at any height of 1.3 m above the floor level
- The number of points in a sub-circuit is not more than 10.
- The maximum load in a single subcircuit is 800W.
What is the allowable frequency variation as per IE rule of safety?
Answer (Detailed Solution Below)
IE Rules Question 15 Detailed Solution
Download Solution PDF- As per the Indian Electricity Rules 1956 (amended up to 25th Nov 2000), the permissible range for grid frequency is ± 3 % of nominal i.e. 48.5 Hz to 51.5 Hz.
- The nominal frequency of operation in the Indian grid is 50.0 Hz and the permissible frequency band specified by Indian Electricity Grid Code (IEGC) is 49.5 Hz to 50.2 Hz with reference to 3rd May 2010.
Some important I.E. rules are given below
IE Rule 50: Supply and use of energy.
IE Rule 54: Declared voltage of supply to the consumer.
IE Rule 55: Declared frequency of supply to the consumer.
IE Rule 30: Service Lines and apparatus on consumer’s premises.
IE Rule 39: Cables protected by bituminous materials.
IE Rule 51: Provisions applicable to medium, high or extra-high voltage installations.
IE Rule 73: Supply to X-ray and high-frequency installation.