Recent questions

A battery of emf E and internal resistance r sends a current, I1 , I2 when connected to an external resistance of R1 , R2 respectively. Find the emf. and internal resistance of the battery.
Answer : Let's derive the expressions for the electromotive force (EMF) and the internal resistance of the battery step-by-step. ### Understanding the Setup The core principle we'll use is Ohm's law applied to the entire circuit. For a ... $$ **EMF (E):** $$ E = \frac{I_1 I_2 (R_1 - R_2)}{I_2 - I_1} $$...

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**....

State and explain Kirchhoff’s law?
Answer : Kirchhoff's laws are two fundamental principles used to analyze electric circuits. They were formulated by Gustav Kirchhoff in 1845 and are based on the conservation of charge ... =blob&qa_blobid=16131873694589351449 [2]: https://electrical-engineering.app/?qa=blob&qa_blobid=10917265924274549047...

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....

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: $v_d = \frac{e\tau}{m}E$....

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....

Why do we prefer a potentiometer to measure the emf of a cell rather than a voltmeter?
Answer : The primary reason we prefer a potentiometer to measure the EMF of a cell is that **a potentiometer draws no current from the cell at the point of measurement.** A voltmeter, by its ... method ensures no current is drawn, thereby eliminating any error caused by the source's internal resistance....

What happens to the resistance of the wire when its length is increased to twice its original length?
Answer : This gets to the core of how resistance works. The short and direct answer is: **The resistance of the wire will double.** Here's a more detailed explanation of why. ### 1. The Simple Explanation (Analogy) Think of the wire ... (x2) | Halves (x0.5) | **Quadruples (x4)** |...

In a potentiometer arrangement, a cell of emf 1.25V gives a balance point at 35.0cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63.0cm , what is the emf of the second cell?
Answer : ### Principle The working principle of a potentiometer is that the potential drop across any portion of a wire of uniform cross-section is directly proportional to the length of that portion, provided a constant current flows ... 2.25 V** ### Answer The EMF of the second cell is **2.25 V**....

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.**...