Hot questions

Explain the phenomenon of loss of magnetism.
Answer : ### The Short Answer Loss of magnetism, also known as **demagnetization**, is the process where a magnetic material loses its magnetic properties. This happens when the microscopic "mini-magnets" inside the material, ... 's own stray field. | A structure slowly eroding due to wind and rain. |...

Explain the use of following tools in carrying out electrical wiring installation: (i) Nose pliers (ii) Test lamps (iii) Crimping tools (iv) Cutter.
Answer : General Introduction In electrical wiring, using the correct tool for the job is not just about efficiency; it is a fundamental requirement for safety and the quality of the finished installation. A poor ... Do not use them to cut steel wire or screws, as this will damage the cutting edges....

State two insulators of following types along with their areas of application: (i) Class A (ii) Class E (iii) Class H
Answer : Here are two examples of insulating materials for each specified class, along with their areas of application. These insulation classes are defined by their maximum allowable operating temperature, ... traction motors (used in trains), which operate under severe thermal and mechanical stress....

Compare the electrical, mechanical and thermal properties of : i) asbestos (ii) mica (iii) porcelain as an insulating material
Answer : ### Classification of Wiring Electrical wiring can be classified based on several criteria, but for installation purposes, it is most commonly classified by the **method of installation and ... is essential for managing the complex electrical needs of kitchens, laundries, and HVAC systems....

Describe with reasons the failure of porcelain insulators.
Answer : ### **Introduction: The Role of Porcelain Insulators** Porcelain insulators are a critical component in electrical power systems. Their primary functions are twofold: 1. **Electrical Insulation: ... , and maintenance strategies (like insulator washing) to ensure the reliability of the power grid....

A cylindrical wire is stretched to increase its length by 10% calculate the percentage increase in resistance?
Answer : The percentage increase in resistance is **21%**. Here is the step-by-step calculation and explanation: ### The Key Concepts 1. **Resistance Formula:** The resistance (R) of a wire is given by: $R = \ ... R_1}{R_1} \times 100\%$ $\text{Percentage Increase} = 0.21 \times 100\% = \bf{21\%}$...

Explain with justification two uses of each of two following as an electrical conductor: (i) Brass (ii) Silver
Answer : ### (i) Brass Brass is an alloy primarily made of copper and zinc. While it is a good electrical conductor, it is not as conductive as pure copper. Its usefulness comes from a ... silver (lowest possible signal loss) while keeping the cost much lower than using a solid silver conductor....

State the need for strictly following safety rules while working in electrical installations.
Answer : Strictly following safety rules while working in electrical installations is not merely a recommendation; it is an absolute necessity. Electricity is an invisible, powerful, and unforgiving hazard. The rules ... protect the worker, their colleagues, the public, and the property they are working on....

A high tension (HT) supply of, say, 6 kV must have a very large internal resistance. Why?
Answer : The primary reason is **safety and current limiting**. Let's use Ohm's Law ($V = IR$) to understand this. A power supply can be modeled as an ideal voltage source ($V_s$) in series ... HT supply for **power transmission** has a very low internal resistance for **efficiency and power delivery**....

Two wires A and B are of the same metal and of same length have their areas of cross section in the ratio 2:1 if the same potential difference is applied across each wire in turn, what will be the ratio of current flowing in A & B ?
Answer : The ratio of the current flowing in wire A to wire B is **2:1**. --- ### Detailed Explanation Let's break down the problem using the relevant physics principles. #### 1. List the Given ... resistance, which is wire A. Our result confirms this: the current in A is twice the current in B....