Hot questions

State significance of earthing. Draw and explain pipe earthing. State the values of earth resistances for : (i) Substation (ii) Residential wiring (iii) H.T. Line (iv) L.T. Line
Answer : ### 1. Significance of Earthing Earthing (or grounding) is a fundamental safety measure in any electrical installation. Its primary significance is to protect people, equipment, and property from ... to consumers. [1]: https://electrical-engineering.app/?qa=blob&qa_blobid=3390146307772186646...

State one condition for maximum current to be drawn from the cell?
Answer : For maximum current to be drawn from a cell, the **external resistance in the circuit should be zero**. This condition is also known as a **short circuit**. **Explanation:** The current (I) drawn from a cell ... possible value is 0. When R = 0, the current is at its maximum value, I_max = E / r....

The storage battery of a car has an emf of 12V . If the internal resistance of the battery is 0.4 Ohm , what is the maximum current that can be drawn from the battery?
Answer : The maximum current that can be drawn from the battery is **30 Amperes (A)**. --- ### Detailed Explanation #### 1. Understand the Concepts * **EMF (Electromotive Force, $\mathcal{E ... even explode. This calculation is a theoretical maximum. **Never attempt to short-circuit a car battery.**...

What is drift velocity? Derive expression for drift velocity of electrons in a good conductor in terms of relaxation time of electrons?
Answer : --- ### Part 1: What is Drift Velocity? In a metallic conductor (like a copper wire), the outer electrons of the atoms are not bound to individual atoms. They are free to move throughout the entire volume of ... field. * The magnitude of the drift velocity is given by: $v_d = \frac{e\tau}{m}E$....

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 |...

With suitable circuit diagram, show how emfs of 2 cells can be compared using a potentiometer?
Answer : ![][1] [1]: https://electrical-engineering.app/?qa=blob&qa_blobid=16022041933233000659 ### **Principle of a Potentiometer** A potentiometer works on the principle that the potential drop ... -section. 4. The current in the primary circuit should be kept constant throughout the experiment....

If the temperature of a good conductor decreases, how does the relaxation time of electrons in the conductor change?
Answer : ### The Short Answer If the temperature of a good conductor decreases, the **relaxation time of electrons increases**. --- ### The Detailed Explanation To understand why, let's break ... **. This is why good conductors become even better conductors (less resistive) at lower temperatures....

If potential difference V applied across a conductor is increased to 2V , how will the drift velocity of the electron change?
Answer : ### Short Answer If the potential difference V applied across a conductor is increased to 2V, the **drift velocity of the electrons will also double**. ### Detailed Explanation Let's ... the electric field, which doubles the force on the electrons, which doubles their average drift velocity....

Write properties of good electrical insulation material.
Answer : ### Introduction An electrical insulator is a material used to prevent the flow of electric current. Its primary job is to confine the current to a desired path (like a conductor wire) and to prevent ... *Chemical & UV Resistance**| High | To ensure long life and reliability in harsh environments. |...

State the procedure for laying / installation of underground cable.
Answer : 1) Direct laying Cable: or Trench laying method: ![][1] [1]: https://electrical-engineering.app/?qa=blob&qa_blobid=2239248645105787017 Procedure:  For laying of a cable trench about 1.5m deep ... one cable does not damage the adjacent cable.  Only armored cables are used in this method. ...