Terminal PD vs EMF: When is PD Greater?

  • Thread starter Thread starter Himal kharel
  • Start date Start date
  • Tags Tags
    Emf Pd
AI Thread Summary
The terminal potential difference (pd) of a cell exceeds the electromotive force (emf) when the cell is charging. The emf represents the pd across the cell's terminals with no current drawn, while terminal voltage is the pd when current is flowing. During charging, terminal voltage is calculated as V=E+Ir, where E is the emf, I is the current, and r is the internal resistance. Conversely, when not charging, terminal voltage is V=E-Ir. Understanding these relationships is crucial for analyzing battery performance in different states.
Himal kharel
Messages
79
Reaction score
0
when is terminal pd greater than emf ?
 
Physics news on Phys.org
You need to explain your terms and circumstances more thoroughly.
 
Terminal pd of a cell exceeds the emf when the cell is charging.
 
Hi, EMF of a cell is the pd across its terminals when no current is drawn from it. Terminal voltage is the PD across a cell when a current is drawn from it. When the circuit drawn current e.m.f is larger than terminal voltage. During charging terminal voltage lags behind the e.m.f.
 
Terminal voltage V=E-Ir , when nod charging. Where,E:EMF of the cell. I:current. r:internal resistance of the cell.
Terminal voltage,V=E+Ir , when charging.
 

Thread 'The Effect of Linear and Rotational Motion on Measured Weight'

Consider an extremely long and perfectly calibrated scale. A car with a mass of 1000 kg is placed on it, and the scale registers this weight accurately. Now, suppose the car begins to move, reaching very high speeds. Neglecting air resistance and rolling friction, if the car attains, for example, a velocity of 500 km/h, will the scale still indicate a weight corresponding to 1000 kg, or will the measured value decrease as a result of the motion? In a second scenario, imagine a person with a...
View full post »

Thread 'Coulomb gauge implies instantaneous radial electric field?'

Scalar and vector potentials in Coulomb gauge Assume Coulomb gauge so that $$\nabla \cdot \mathbf{A}=0.\tag{1}$$ The scalar potential ##\phi## is described by Poisson's equation $$\nabla^2 \phi = -\frac{\rho}{\varepsilon_0}\tag{2}$$ which has the instantaneous general solution given by $$\phi(\mathbf{r},t)=\frac{1}{4\pi\varepsilon_0}\int \frac{\rho(\mathbf{r}',t)}{|\mathbf{r}-\mathbf{r}'|}d^3r'.\tag{3}$$ In Coulomb gauge the vector potential ##\mathbf{A}## is given by...
View full post »

Thread 'Simple thought experiment with Stefan-Boltzmann law: energy'

Dear all, in an encounter of an infamous claim by Gerlich and Tscheuschner that the Greenhouse effect is inconsistent with the 2nd law of thermodynamics I came to a simple thought experiment which I wanted to share with you to check my understanding and brush up my knowledge. The thought experiment I tried to calculate through is as follows. I have a sphere (1) with radius ##r##, acting like a black body at a temperature of exactly ##T_1 = 500 K##. With Stefan-Boltzmann you can calculate...
View full post »

Similar threads

Are lost volts the difference between EMF and terminal potential difference?
Replies
4
Views
2K
Any Edexcel A Level Physics Teachers Here - Paper 1 Q13?
Replies
13
Views
1K
B EMF induced by Bar Magnet falling through a Coil
Replies
3
Views
650
Chemistry Solving H2/Pd/C Reduction for #5 & #6 Questions
Replies
6
Views
3K
Converting oscilloscope voltage to laser power
Replies
12
Views
2K
Difference in EMF of 5000 V and a voltmeter reading of 40 V
Replies
22
Views
3K
Internal resistance proportional to current?
Replies
3
Views
3K
Why Does Terminal Voltage Differ from EMF in a Circuit?
Replies
15
Views
5K
Unable to understand how higher current results in lower p.d
Replies
5
Views
1K
Voltmeter problem from (OCR paper) multiple choice
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top