Estimation and Costing MCQ Quiz - Objective Question with Answer for Estimation and Costing - Download Free PDF

Material Schedule and Detailed Estimation

Definition: A material schedule and detailed estimation are essential components of project planning and execution in industrial installations. These documents provide a comprehensive list of materials required for the project, along with their quantities, specifications, and associated costs. The primary purpose of preparing a material schedule and detailed estimation is to ensure accurate planning, budgeting, and efficient resource allocation for successful project completion.

Purpose and Importance:

Preparing a material schedule and detailed estimation serves several critical purposes in an industrial installation project:

• Accurate Budgeting: By identifying all the materials required for the project and their costs, the project team can establish an accurate budget. This minimizes the risk of cost overruns and ensures that adequate financial resources are allocated to the project.
• Efficient Resource Allocation: A detailed material schedule helps in the efficient procurement and allocation of materials. This ensures that the right materials are available at the right time, preventing delays in project execution.
• Project Planning: A comprehensive material schedule is a critical input for project planning. It helps in defining the project timeline, identifying potential risks, and developing mitigation strategies.
• Quality Assurance: By specifying the exact materials and their specifications, the material schedule ensures that the project meets the required quality standards and performance criteria.
• Minimizing Waste: Detailed estimation helps in avoiding over-ordering or under-ordering of materials, reducing material wastage and associated costs.
• Transparency and Accountability: A well-documented material schedule promotes transparency in procurement and project execution, ensuring accountability among stakeholders.

Correct Option Analysis:

The correct option is:

Option 1: To provide a comprehensive list of materials and costs for accurate project planning and execution.

This option accurately describes the primary purpose of preparing a material schedule and detailed estimation. These documents are essential tools for project managers and engineers to plan, budget, and execute industrial installation projects effectively. By providing a detailed list of materials and their associated costs, the material schedule ensures that the project is completed on time, within budget, and to the desired quality standards.

Important Information

To further understand the analysis, let’s evaluate the other options:

Option 2: To eliminate the need for protective devices in the system.

This option is incorrect. A material schedule and detailed estimation do not eliminate the need for protective devices in an industrial system. Protective devices such as circuit breakers, fuses, and safety valves are critical components of any industrial installation to ensure safety and prevent equipment damage. These devices are included in the material schedule as part of the overall project requirements.

Option 3: To focus only on the aesthetic aspects of the installation.

This option is also incorrect. While aesthetics may be a consideration in certain projects, the primary purpose of a material schedule and detailed estimation is to ensure accurate planning, budgeting, and execution of the project. Aesthetic aspects, if relevant, are a secondary consideration and are typically addressed during the design phase.

Option 4: To ensure the project is completed without any documentation.

This option is incorrect and contradicts the purpose of preparing a material schedule and detailed estimation. Documentation is a fundamental aspect of any industrial project, ensuring transparency, accountability, and compliance with regulatory requirements. A material schedule and detailed estimation are critical components of project documentation.

Conclusion:

In conclusion, the preparation of a material schedule and detailed estimation is a vital step in the planning and execution of industrial installation projects. It provides a comprehensive list of materials and costs, enabling accurate budgeting, efficient resource allocation, and effective project planning. The correct option, Option 1, highlights the primary purpose of this process, which is essential for the successful completion of the project. The analysis of the other options demonstrates their inaccuracies and reinforces the importance of documentation, safety, and quality in industrial installations.

Explanation:

Primary Purpose of Estimation in Electrical Installations

Definition: Estimation in electrical installations refers to the process of predicting the cost, materials, and time required to complete an electrical project. It involves detailed calculations and planning to ensure the project is executed efficiently and within budget.

Working Principle: The estimation process begins with analyzing the project requirements, which includes understanding the design specifications, identifying the necessary equipment, and determining the scope of work. Based on these inputs, estimators calculate the total cost, including labor, materials, transportation, and other overheads. Additionally, timelines are drafted to ensure the project is completed within the stipulated period.

Advantages:

• Provides clarity on the financial and resource requirements of the project.
• Ensures that the project is completed within budget and avoids unnecessary expenses.
• Helps identify potential risks and challenges before the project begins.
• Enables efficient allocation of resources, such as manpower and materials.
• Facilitates better communication between stakeholders by providing a clear roadmap.

Disadvantages:

• Relies heavily on accurate data; any discrepancies can lead to errors in estimation.
• Requires skilled professionals with experience in electrical installations and costing.
• Time-consuming process, especially for large-scale projects.

Applications: Estimation is crucial in various electrical installation projects, including residential, commercial, and industrial setups. It is used for tasks such as wiring systems, installation of electrical appliances, power distribution systems, and more.

Correct Option Analysis:

The correct option is:

Option 4: To predict the cost, materials, and time required for completing an electrical project.

This option accurately describes the primary purpose of estimation in electrical installations. The estimation process is designed to provide a comprehensive overview of the project's requirements, including financial, material, and time-related aspects. By doing so, it ensures that the project is executed efficiently, cost-effectively, and within the desired timeframe.

Important Information

To further understand the analysis, let’s evaluate the other options:

Option 1: To ensure compliance with aesthetic design standards.

This option is incorrect as it focuses on aesthetic aspects, which are secondary considerations in electrical installations. While aesthetics can be important, they are not the primary purpose of estimation. Estimation primarily deals with financial and material planning rather than design standards.

Option 2: To focus solely on the operation and maintenance of electrical systems.

This option is incorrect because operation and maintenance pertain to the post-installation phase of electrical systems. Estimation is conducted before the project begins and is aimed at planning and budgeting rather than operational aspects.

Option 3: To replace the need for protective devices in electrical systems.

This option is incorrect and misleading. Protective devices are essential components of electrical systems, ensuring safety and preventing damage. Estimation does not replace the need for these devices; rather, it includes their cost and specifications in the overall budget.

Option 5: (Option not provided in the context).

No details are provided for Option 5; hence, it cannot be analyzed. However, based on the given options, the correct answer remains Option 4.

Conclusion:

Estimation is a critical step in electrical installations, serving as the foundation for effective project planning and execution. It ensures that the project is completed within budget, on time, and with the required resources. While other aspects such as aesthetics, operation, and safety are important, they are secondary to the primary purpose of estimation, which is to predict costs, materials, and timelines.

The correct answer is option 3.

National Electric Code (NEC) 2011

The primary scope of the National Electrical Code (NEC) 2011 is to provide a set of guidelines for the safe installation and use of electrical wiring and equipment. It focuses on minimizing hazards and preventing accidents, injuries, and fires related to electrical installations. 

Safety: The NEC prioritizes safety by outlining general safety procedures, providing recommendations for safe practices, and addressing specific hazards. 

Electrical Installations: The code applies to various types of electrical installations, including those in buildings, industrial sites, and even outdoor locations. 

Equipment and Wiring: The NEC covers the selection, installation, and maintenance of electrical equipment and wiring, ensuring they meet safety standards. 

Hazardous Areas: The code includes provisions for special precautions in areas with explosive or otherwise dangerous atmospheres. 

The correct answer is option 4.

This is indeed the correct and most critical factor because:

• Accurate power calculation ensures the system is appropriately sized and avoids overload. Protective devices (like circuit breakers, fuses, overload relays) are essential to prevent equipment damage and ensure safety.
• Power calculations ensure the motor, cables, and supply system are appropriately sized.

The correct answer is option 2.

Compliance with electrical codes (like NEC, IEC) and safety standards is crucial in any commercial electrical installation. It ensures:

• Safety of occupants and maintenance personnel.
• Legal compliance to avoid penalties, rework, or shutdowns.
• Accurate costing, since estimates include only approved materials and proper labor practices.
• System reliability reduces the chance of electrical faults or fire.

Ignoring these codes can result in failed inspections, costly legal consequences, or dangerous systems.

The cheapest system of wiring is cleat wiring.

1. Horizontal strip earthing: This type of earthing is used at places which have rocky earth bed.
2. Rod earthing: This system of earthing is suitable for areas which are sandy in character. This system of earthing is very cheap as no excavation work is involved.
3. Plate earthing: It is used for larger stations and transmission lines, where the fault current, likely to be high.
4. Pipe earthing: It is used for ordinary soil or dry and rocky soil. The size of the pipe depends upon the current to be carried and the type of the soil. Usually, the pipe used for this purpose is of diameter 38 mm and 2.5 meters in length for ordinary soil or of greater length in case of dry and rocky soil.

• Pipe earthing is the most common and best system of earthing as compared to other systems suitable for the same earth and moisture conditions.
• Pipe earthing is the best form of earthing and is very cheap in cost.
• In this method the galvanized steel and perforated pipe of approved length and diameter in place upright in permanently wet soil.
• The size of the pipe depends upon the current to be carried and the type of soil.

The correct answer is option 3.

​Earnest money deposit

• It is a small refundable fee collected by the department from each bidder to ensure that a bidder does not submit a dummy bid or back out at the time of tender opening.
• It is returned when all the bids are opened & tender is awarded to another firm.
• It is generally 2% of the tender value.

Security deposit

• It is the amount of money that has to be deposited with the buyer once the tender is awarded to a bidder to ensure that if he does not complete the task as per the work order, the buyer can recover the loss by forfeiting his security deposit.
• It can be in the form of a demand draft or bank guarantee.
• When the contractor completes the project, he gets its security deposit returned.
• ​It is generally 10% of the tender value.

Additional Information Caution money:

• It is the amount of money that someone has to pay when they rent property, use a service, etc. which will not be refunded if they damage something or owe money at the end of their contract.

Bank guarantee:

• It is a written contract given by a bank on behalf of a customer that undertakes to pay or discharge the liability of the debtor in case of any default.

The minimum clearing distance between the equipment for the 750 to 1000 kV line must be 45 feet.

The minimum clearing distance that equipment should keep from the power lines of different voltage levels is:

The symbol of different Transformer is shown below:

Concept:

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

I_FL = 2400 / 240 = 10 A

According to IE Rule 48:

\({I_{lek}} = \frac{{{I_{FL}}}}{{5000}} = \frac{{10}}{{5000}} = 0.002\;A\)

∴\(IR = \frac{{supply\;voltage}}{{{I_{lekage}}}} = \frac{{240}}{{0.002}} = 120,000 = 0.12\;M{\rm{\Omega }}\)

The desired minimum depth of laying from the ground surface to the top of the cable is as follows:

High voltage cables (3.3 kV to 11 kV rating) = 0.9 m

High voltage cables (22 kV, 33 kV rating) = 1.05 m

Low voltage and control cables = 0.75 m

Different 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:

Concept:

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, I_FL = 7.5 A

According to IE Rule 48:

\({I_{lek}} = \frac{{{I_{FL}}}}{{5000}} = \frac{{7.5}}{{5000}} = 0.0015\;A\)

∴\(IR = \frac{{supply\;voltage}}{{{I_{lekage}}}} = \frac{{240}}{{0.0015}} = 160,\;000 = 0.16\;M{\rm{\Omega }}\)