Hot questions

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 the help of a circuit diagram, how the value of an unknown resistance can be determined using a Wheatstone bridge?
Answer : ![][1] [1]: https://electrical-engineering.app/?qa=blob&qa_blobid=407323477172242274 ### **Introduction** A Wheatstone bridge is an electrical circuit used for the precise measurement of an ... (R₃) at the balance point has been recorded, the unknown resistance Rₓ can be calculated precisely....

A low voltage supply from which one needs high currents must have very low internal resistance. Why?
Answer : ### The Simple Analogy: A Water Pipe Imagine your power supply is a large water tank (representing the voltage) and you need to get a high flow of water (high current) out of a pipe at ... extremely small, this will generate a massive amount of heat, which can damage or destroy the power supply....

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**....

What are ohmic and non-ohmic resistors? Give one example of each?
Answer : **Ohm's Law** states that the voltage ($V$) across a conductor is directly proportional to the current ($I$) flowing through it, provided all physical conditions and temperature remain constant. Mathematically, ... | **Carbon Resistor**, Nichrome Wire | **Filament Light Bulb**, Diode, Thermistor |...

Name any one material having a small value of temperature coefficient of resistance. Write one use of this material?
Answer : **Material:** **Manganin** (an alloy of copper, manganese, and nickel) **Use:** Due to its very low temperature coefficient of resistance, it is used to make ** ... for electrical measuring instruments like ammeters and Wheatstone bridges, where a stable and predictable resistance is essential....

A set of n-identical resistors, each of resistance R ohm when connected in series have an effective resistance of X ohm and when the resistors are connected in parallel the effective resistance is Y ohm. Find the relation between R , X and Y ?
Answer : Let's break this down step-by-step to find the relationship between R, X, and Y. ### 1. Resistors in Series When resistors are connected in series, their total effective resistance is the sum of ... the **geometric mean** of the total series resistance (X) and the total parallel resistance (Y)....

Explain the suitability of copper as an electrical conductor with reference to its mechanical and electrical properties.
Answer : ### Introduction Copper is the industry standard for electrical wiring and conductors, and its widespread use is due to an exceptional combination of both electrical and mechanical properties. While ... for decades, making it the superior choice for the vast majority of electrical applications....

Draw the graph showing the variation of conductivity with temperature for a metallic conductor?
Answer : The conductivity for a metallic conductor decreases with the increase in temperature. ![][1] [1]: https://electrical-engineering.app/?qa=blob&qa_blobid=10491891827766109637 ### Explanation: The Physics Behind the Graph To understand this ... | **Low** |...

State why the resistance of the conductor increases with the rise in temperature.
Answer : Here is a clear explanation of why the resistance of a conductor increases with a rise in temperature, broken down into a simple analogy and the underlying physics. --- ### Simple Analogy: The ... More collisions** mean more opposition to the flow, which is, by definition, **higher resistance**....