Stored charege and potentials of two capacitors in series

AI Thread Summary
Two capacitors, 2.0F and 5.0F, connected in series to a 1.5V battery have an equivalent capacitance of 1.429F. The charge stored on each capacitor is 2.143 coulombs. The potential difference across the 2.0F capacitor is 1.072V, while across the 5.0F capacitor, it is 0.429V. Both methods used to calculate the charge and voltage yield consistent results. The calculations confirm the principles of series capacitance and voltage division.
zoner7
Messages
89
Reaction score
0

Homework Statement


Two capacitors of 2.0F and 5.0F are connected in series; the combination is connected to a 1.5 volt battery. What is the charge stored on each capacitor? What is the potential difference across each capacitor?


Homework Equations


C = Q / (Delta)V

The Attempt at a Solution



Since the capacitors are in series, we can find the equivalent capacitance by solving:

1/Ceq = 1/2.0F + 1/5.0F
Ceq = 1.429F

I then used this value to find the charge on each plate of each capacitor

C = Q/V
CV = Q
1.429F * 1.5V = 2.143

So now I now the amount of charge on each plate.

Using this value in conjunction with a specific capacitance, I can find the potential difference across any given capacitor whose capacitance I know.

so, V = Q/C
2.143/2 = 1.072V
2.143/5 = .429V

Thank you for the help.
 
Physics news on Phys.org


All correct, I think. I used a slightly different method, adding the voltages around the loop to get Q/2 + Q/5 = 1.5
which yields the same answer you got.
 
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...
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...
Back
Top