Question

Can someone explain the following: ∆U= Q∆V but Ucapacitor= 1/2QV? In other words, why is the...

Can someone explain the following:

∆U= Q∆V but Ucapacitor= 1/2QV?

In other words, why is the potential energy of capacitor multiplied by 1/2 but the change in PE is not?

Science   Physics   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

The potential energy of the capacitor is given by,

In the above equation the capacitance C of a capacitor is constant, and when potential energy changes the potential will change. (In the first equation both charge and voltage are both variables, and they both can change for change in potential energy).

Taking derivative of the potential energy with respect to voltage we can write,

The differentials can be approximated by small change, hence we can write,

We know that Q = CV. Hence we can write,

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Explain why this works: if one dimension, if we have a potential energy function U(x) along...
Explain why this works: if one dimension, if we have a potential energy function U(x) along with initial values for x and v, we can determine x and v for all subsequent times.
a)show that the potential energy on a capacitor is U=Q^2/(2c) for a capacitor C holding charge...
a)show that the potential energy on a capacitor is U=Q^2/(2c) for a capacitor C holding charge Q. b)what is the total capaciatnce of 5 eqqual capacitors C connected in paralledl? in series? c)Two parallel plate capacitors are connected in series.Both are filled with a dielectric with constant K.One capacitor had plates of area A1 seperated by distance d1, the other has plate of area A2 seperated by distance d2.What is the toal capacitance of the two connected in series.
U (potential energy)=(k q1 q2)/r=V¬1 (voltage)*q2 ; Ekin = (1/2) m v2 How much energy must...
U (potential energy)=(k q1 q2)/r=V¬1 (voltage)*q2 ; Ekin = (1/2) m v2 How much energy must a single electron have as it leaves a 1.5 V potential assuming it started from rest? How fast must that electron be moving as a result? How much energy can that electron release before it comes to a stop, and why?
A parallel plate capacitor with plate separation d is connected to a battery. The capacitor is...
A parallel plate capacitor with plate separation d is connected to a battery. The capacitor is fully charged to Q Coulombs and a voltage of V Volts. (C is the capacitance and U is the stored energy.) Select true or false for each statement. 1)With the capacitor connected to the battery, inserting a dielectric with κ > 1 will decrease U. 2)With the capacitor connected to the battery, decreasing d increases C. 3)After being disconnected from the battery, decreasing d...
1. Let u(x) and v(x) be functions such that u(1)=2,u′(1)=3,v(1)=6,v′(1)=−1 If f(x)=u(x)v(x), what is f′(1). Explain...
1. Let u(x) and v(x) be functions such that u(1)=2,u′(1)=3,v(1)=6,v′(1)=−1 If f(x)=u(x)v(x), what is f′(1). Explain how you arrive at your answer. 2. If f(x) is a function such that f(5)=9 and f′(5)=−4, what is the equation of the tangent line to the graph of y=f(x) at the point x=5? Explain how you arrive at your answer. 3. Find the equation of the tangent line to the function g(x)=xx−2 at the point (3,3). Explain how you arrive at your answer....
1. Can someone explain why this set is unbound closed set( -infinity,0 ] obviously, the upper...
1. Can someone explain why this set is unbound closed set( -infinity,0 ] obviously, the upper bound is 0 because of ] but why it is actually unbounded set? Please follow the comment. 2. why open subset can lead us to convergence. I don't understand it. Please give me some example or other theorem to support it
How is this possible? (in other words, why are the powers different) K= Q( i, sqrt(2))...
How is this possible? (in other words, why are the powers different) K= Q( i, sqrt(2)) is the root field over Q of x^4 - 2x^2 + 9, and it's the root field over Q(sqrt(2) of x^2 - 2(sqrt(2))x + 3
Let f(u, v) = u TMv be a bilinear function. Is f an inner product? explain...
Let f(u, v) = u TMv be a bilinear function. Is f an inner product? explain why! M = 2 2 2 2
Suppose u = (u1,u2) and v = (v1, v2) are two vectors in R2. Explain why...
Suppose u = (u1,u2) and v = (v1, v2) are two vectors in R2. Explain why the operations (u * v) = u1v2 cannot be an inner product.
Respond to the following in a minimum of 175 words: Why does the vertical component of...
Respond to the following in a minimum of 175 words: Why does the vertical component of velocity for a projectile change with time, whereas the horizontal component of velocity does not? How can the conservation of energy help us explain these concepts?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT