New answers tagged

0

I think that you have faced a conceptual problem because you have used the relationship $V=RI$, rather you should have been using the definition of resistance $R = \frac V I$. Then as $V$ goes up and $I$ goes down the value of $R$ increases. Also you must be careful about $I=0$ (current equals exactly zero) and $I\rightarrow0$ (current gets closer and closer ...


0

Bear in mind that infinite resistance is equal to an open circuit. In real life if you have a battery not connected to anything, there will always be a voltage across the terminals. Even a lead-acid car battery will produce sparks if you short the terminals!


-1

At R→∞ voltage won't be 0 but little less than EMF off cell, since a series circuit with voltmeter and battery is complete. Yes, voltage across resistor reaches 0.Voltmeter reading is not EMF because it draw some current which pass through internal r and gets some potential across it. An Ideal voltmeter cannot tell you voltage across resistance in ...


0

-First, I'm trying to grasp the concept of why and how the voltage drop at the terminals of a battery depends on the resistance of the circuit. The EMF, $\mathcal{E}$, exists chemically and is always present. If there is a path for current to flow, then there will be a voltage drop across the internal resistance, $r$, and the external resistance, $R$. ...


1

I actually did this for a battery control driver for a tablet. The only way I found to do it was to take manufacturers charge/discharge curves as functions of temperature and number of cycles and encode them by hand in a lookup table. This does assume that the manufacturer has enough data, the data is accurate, and is willing to supply it.


1

As someone who did a degree in physics before moving into electronics and s/w R&D, my experience would suggest "yes". Over the years I have been involved in a number of projects that could be classified as experimental physics, and in all cases knowledge of electronics was a vital part. At the very least a physicist should be able to read a circuit ...


0

Physics is about making models of the world, if you can make them as accurate as possible why wouldn't you? Incidentally, sometimes you really need acuracy as the smallest difference in your initial conditions can make a great difference in your outcome (see chaotic systems, the best example is weather or the double pendulum) Imagine instead of taking ...


0

The live wire oscillates and either drains or supplies electricity to the neutral wire. The live wire oscillates between 230V to -230V and the neutral wire always stays 0V.



Top 50 recent answers are included