Find R: Internal Resistance Equation

AI Thread Summary
To find the internal resistance r of a battery using the equation r = (E - V) / V * R, one must know the electromotive force (emf) E, the terminal voltage V, and the resistance of the voltmeter R. The discussion clarifies that R is necessary for calculating r, but the user is unsure how to determine R. Understanding the relationship between these variables is crucial for solving the equation. The focus remains on the algebraic manipulation needed to isolate and calculate the internal resistance.
heelp
Messages
23
Reaction score
0
In this equation I r= E-V/V*R


How would I find R? thanks in advance you your help.
 
Physics news on Phys.org
What do you mean? Are you asking about how to do the algebraic manipulations? And where are the parens in your equation?
 
Oops. r= (E-V/v)*R

This equation shows that knowing the emf E, the voltmeter's reading of the terminal voltatge V, and the resistance of the voltmeter R, the unknown internal resistance r of the battery can be computed.


I'm trying to find r. I know E,AND V. But I don't know how to find R.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

How to solve for EMF and internal resistance in a circuit?
Replies
8
Views
3K
Internal Resistance Affect the Balancing Length in a Potentiometer?
Replies
12
Views
962
Current through a circuit when the key is open
Replies
42
Views
5K
Batteries in series, parallel, and internal resistance
Replies
24
Views
5K
Finding the internal resistance of battery
Replies
10
Views
3K
Parallel circuit with internal resistance
Replies
6
Views
2K
Current through an inductor as a function of time
Replies
10
Views
379
Need help with a question on potential difference
Replies
7
Views
1K
A falling resistive disk in uniform magnetic field
Replies
17
Views
1K
Calculating EMF and Internal Resistance: A Practical Guide
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top