Physics Homework problem: Dielectrics

AI Thread Summary
The discussion revolves around a physics homework problem involving a 3500 air-gap capacitor connected to a 32V battery and the effect of inserting mica as a dielectric. Participants clarify the initial charge calculation for the air-gap capacitor, with the charge determined to be 1.12E-4 C. The dielectric constant for mica (K=7) is discussed, highlighting its impact on capacitance. There is some confusion regarding the capacitor's specifications, specifically whether it is measured in microfarads or nanofarads. Ultimately, the original poster resolves the problem independently and expresses gratitude for the assistance.
Jscrub
Messages
15
Reaction score
0
I cannot figure out this problem...can someone help me?

A 3500 air-gap capacitor is connected to a 32 battery.

If a piece of mica fills the space between the plates, how much charge will flow from the battery?


Express your answer using two significant figures.
 
Physics news on Phys.org
Welcome to PF!

Hi Jscrub! Welcome to PF! :wink:

First, how much charge will flow from the battery when the gap is just air?

Second, what equations do you know about how a dielectric affects a field or a capacitor? :smile:
 
c= KCo

c=Q/V

Q Air = 1.12E-4
 
v= 32 V

K(mica) = 7

K (air) = 1.0006

so, Co= 1.12E-4
 
Jscrub said:
A 3500 air-gap capacitor is connected to a 32 battery.

What is a 3500 air-gap capacitor?

Is that a 3500μf capacitor or 3500nf?

What is the effect of the dielectric on the capacitance?

I don't follow your conclusion
so, Co= 1.12E-4

Haven't you added a dielectric to your capacitor?
 
The above was not a conclusion..it was just a reply to the previous person...

Co = 3500E-9...

But it is fine..I don't need anymore help...I figured it out...

Thanks
 
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 »

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 »

Similar threads

Why can we model spherical capacitor with two dielectrics as two capacitors in series?
Replies
4
Views
2K
Calculations involving different Dielectrics and Capacitors
Replies
7
Views
2K
Electric field between capacitor plates when a dielectric slab is inserted
Replies
14
Views
2K
Which of the two dielectrics breaks down first?
Replies
2
Views
1K
Changes in capacitor after dielectric inserted
Replies
17
Views
3K
Question about charged capacitors and inserting a dielectric into one
Replies
3
Views
2K
A 3500-pF air-gap capacitor question
Replies
2
Views
4K
Find Dielectric Constant from Parallel Plate Capacitor Problem
Replies
1
Views
2K
Finding Minimum Plate Separation for Mica-Filled Capacitor
Replies
6
Views
4K
How Does Inserting Different Dielectric Materials Affect Capacitor Performance?
Replies
9
Views
2K

Hot Threads

Recent Insights

Back
Top