Demand Factor MCQ Quiz in தமிழ் - Objective Question with Answer for Demand Factor - இலவச PDF ஐப் பதிவிறக்கவும்

Explanation:

Demand Factor

Definition: The demand factor is a measure used in electrical engineering to describe the ratio of the maximum demand of a system (or equipment) to its total connected load. It provides insight into how efficiently the connected load is being utilized during peak demand periods. Mathematically, the demand factor is expressed as:

Demand Factor (DF) = Maximum Demand ÷ Total Connected Load

The demand factor is primarily used in power system analysis and design to ensure that electrical installations are appropriately sized and optimized for their intended use.

Working Principle:

The demand factor is always less than or equal to 1 because the maximum demand of a system cannot exceed the total connected load. In most real-world scenarios, the demand factor is less than 1, as not all connected devices and equipment are simultaneously operating at their maximum rated capacity.

Applications:

• Electrical load calculation for designing power systems.
• Optimizing the size of transformers, generators, and distribution systems.
• Energy efficiency analysis to identify potential areas for reducing power consumption.

Correct Option Analysis:

The correct option is:

Option 3: It is always less than or equal to 1.

This statement is correct because the demand factor is a ratio between the maximum demand of a system and its total connected load. Since the maximum demand can never exceed the total connected load, the demand factor is always ≤ 1. This property is fundamental to the concept of the demand factor, and it holds true in all practical scenarios.

Important Information

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

Option 1: It is always greater than 1.

This option is incorrect because the demand factor cannot be greater than 1. The maximum demand of a system cannot exceed its total connected load, as this would imply that the system is operating at a capacity beyond its designed limits, which is not possible.

Option 2: It is always equal to the utilization factor.

This option is incorrect because the demand factor and utilization factor are distinct concepts. The utilization factor refers to the ratio of the actual energy used by a system to the maximum energy it could use over a given period. While both factors are used to assess system efficiency, they measure different aspects of electrical system performance.

Option 4: It is always equal to the diversity factor.

This option is incorrect because the diversity factor is a separate concept from the demand factor. The diversity factor is the ratio of the sum of individual maximum demands of various components of a system to the maximum demand of the entire system. It is used to account for the probability that not all components will operate at their maximum demand simultaneously. Demand factor and diversity factor are related but are not the same.

Option 5: (No content provided for this option in the prompt.)

Conclusion:

The demand factor is an essential metric in electrical engineering, providing critical insights into system efficiency and design optimization. It is always less than or equal to 1, as the maximum demand cannot exceed the total connected load. Understanding this concept helps engineers design systems that are both cost-effective and capable of meeting peak demand requirements without overloading or underutilizing resources.

Demand factor: It is defined as the ratio of maximum demand on the power station to its connected load.

Demand factor = Maximum demand / Total connected load

Concept:

Demand factor:

It is the ratio of maximum demand on the power station to its connected load i.e.,

Demand factor = (maximum demand)/(connected load)

The value of the demand factor is usually less than 1.  It is expected because the maximum demand on the power station is generally less than the connected load.

Calculation:

Given,

15 lamps have 60 W each

Operated as follows

5 lamps for 2hrs

10 lamps for 2hrs

6 lamps for 2hrs

Total connected load = 15 × 60 W = 900 W.

Daily energy consumption = ( 5×2 + 10×2 + 6×2) × 60 W  = 2520 Wh.

Maximum load = 10 × 60 W = 600 W   (during 8 pm – 10 pm)

Demand factor\(\; = \frac{{600}}{{900}} \times 100 = 66.667\% \)