Charging and discharging capacitors  current time graphby jsmith613 Tags: capacitors, charging, current, discharging, graph, time 

#1
Apr312, 08:23 AM

P: 614

1. The problem statement, all variables and given/known data
why is the currenttime graph for a charging AND discharging capacitor the same? 2. Relevant equations 3. The attempt at a solution Q=It so for a discharging capacitor as time goes on the charge stored decreases so current decreases BUT for a charging capacitor charge increases so current should increase?? 



#2
Apr312, 09:32 AM

Mentor
P: 11,416

Think in terms of the potential difference that is driving the current. How much of the potential appears across the resistor over time?




#3
Apr312, 11:42 AM

P: 614





#4
Apr312, 11:46 AM

Mentor
P: 11,416

Charging and discharging capacitors  current time graph 



#5
Apr312, 12:52 PM

P: 614

I think so...




#6
Apr312, 01:05 PM

Mentor
P: 11,416

Sketch the PD across the capacitor for the charging case. You should be able to infer the PD across the resistor using KVL for the circuit (battery, resistor, capacitor). What do you find?




#7
Apr312, 01:09 PM

P: 614





#8
Apr312, 01:46 PM

Mentor
P: 11,416





#9
Apr312, 03:11 PM

P: 614

no idea about resistor, sorry :( 



#10
Apr312, 03:19 PM

Mentor
P: 11,416





#11
Apr312, 04:18 PM

P: 614

V = V_{1} + V_{2}
so I would presume the emf across the resistor falls as p.d across capacitor increases (and then increases as p.d across capacitor decreases) 



#12
Apr312, 04:39 PM

Mentor
P: 11,416





#13
Apr312, 04:43 PM

P: 614

it is only involved during discharging surely your approach is wrong? 



#14
Apr312, 04:49 PM

Mentor
P: 11,416





#15
Apr312, 04:56 PM

Mentor
P: 11,416





#16
Apr312, 05:30 PM

P: 614





#17
Apr312, 05:40 PM

Mentor
P: 11,416





#18
Apr312, 05:53 PM

P: 614




Register to reply 
Related Discussions  
Charging and Discharging capacitors  Introductory Physics Homework  1  
how to simulate capacitor charging n discharging current in multisim for RC circuit ?  Electrical Engineering  0  
charging and discharging of capacitors  Introductory Physics Homework  7  
Charging / Discharging Capacitors In Series  Electrical Engineering  14  
Cascading RC circuit w/ DC voltage. How will capacitors charging time vary?  Introductory Physics Homework  5 