Calculating EMF and Current in a Circuit with Internal Resistance

AI Thread Summary
To calculate the current in a circuit with a 5.60-ohm resistor and a battery with 0.200-ohm internal resistance and a terminal voltage of 10.0V, the formula EMF = terminal voltage + (I)(Rint) is used. The current (I) can be derived from the equation 10 = 5.6I, resulting in I = 1.79A. The EMF of the battery is then calculated as EMF = 10 + (1.79)(0.2), yielding an EMF of approximately 10.36V. Clarification on the resistor's value is necessary, as there is a discrepancy between 5.6 and 5.8 ohms mentioned in the discussion. Understanding these calculations is crucial for exam preparation.
Gunner1412
Messages
4
Reaction score
0

Homework Statement



A 5.60ohm resistor is connected to a battery that has 0.200ohm internal resistance, and a terminal voltage of the battery is 10.0V. What is the current in the resistor? What is the emf of the battery?

Homework Equations



EMF=terminal voltage+(I)(Rint.)
V=RI

The Attempt at a Solution


E-I1Ri-I1R1=0
10=5.8I
I=1.72.
EMF=10+0.344=10.34

Help guys? Exam tomorrow at nine and this is the last problem I don't understand! Very much appreciated :)
 
Physics news on Phys.org
Gunner1412 said:

The Attempt at a Solution


E-I1Ri-I1R1=0
10=5.8I
I=1.72.
EMF=10+0.344=10.34
Looks good. (But is the resistor 5.6 or 5.8 ohms?)
 
5.6+0.2 for R1+ri... no?
 
E-I1Ri-I1R1=0
10=5.8I
I=1.72.
EMF=10+0.344=10.34
The terminal voltage is the voltage across the resistance. So V = IR1.= ER1/(R1 + Ri ).
 
Last edited:
Gunner1412 said:
5.6+0.2 for R1+ri... no?
No, 10V is the terminal voltage, which equals EMF - Iri. Thus 10 = I*5.6. (From your equation: E-I1Ri-I1R1=0.)
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Unraveling the Mystery of EMF Internal Resistance
Replies
2
Views
2K
Potential difference of an emf with internal resistance
Replies
4
Views
2K
How to solve for EMF and internal resistance in a circuit?
Replies
8
Views
3K
Why do the headlights on the car become dim when the car is starting?
Replies
4
Views
2K
Potentiometer and EMFs with internal resistance
Replies
4
Views
3K
Connecting a number of EMF sources in a circle to form a circuit
Replies
9
Views
1K
Internal Resistance of a Car Battery
Replies
8
Views
13K
Find Internal Resistance From 2 Circuits w/ The Same Battery
Replies
2
Views
2K
Finding internal resistance & EMF of a battery in a circuit
Replies
11
Views
6K
Calculating EMF and Internal Resistance: A Practical Guide
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top