Past exam question about electrostatic field and potential

In summary, using Stoke’s theorem and the given identities, it can be shown that the electrostatic field E and the potential ψ at a point in space are related by the equation E = -∇ψ. This is achieved by considering the circulation integral ∫E*ds and applying Stokes’ theorem to show that the curl of E must always be zero. This implies the existence of a potential function V such that E = -∇V, which is the desired relationship between E and ψ.
  • #1
ZedCar
354
1

Homework Statement



Using Stoke’s theorem and the identities given, ∇x∇(Scalar)=0 deduce the relationship between electrostatic field E and potential ψ at a point in space, show that E = -∇ψ


Homework Equations





The Attempt at a Solution



Does this question mean show a derivation which uses Stoke’s theorem and mathematical identities to obtain E = -∇ψ ?

Or is something else required since it states, "∇x∇(Scalar)=0 deduce the relationship between electrostatic field E and potential ψ at a point in space". I wasn't sure if by a derivation arriving at E = -∇ψ then in effect this would be illustrated.

Thanks
 
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  • #2
Can't read your question. What is ∇x∇(Scalar)=0 ?
 
  • #3
rude man said:
Can't read your question. What is ∇x∇(Scalar)=0 ?

That's exactly the way its typed on the past exam paper ie ∇x∇(Scalar)=0
 
  • #4
rude man said:
Can't read your question. What is ∇x∇(Scalar)=0 ?
Isn't that just the vector calculus identity that the curl of a gradient is zero?
 
  • #5
Fightfish said:
Isn't that just the vector calculus identity that the curl of a gradient is zero?

Yes, this is an identity.
 
  • #6
OK, I can't read the del sign in your posts. But OK, no problem now.

Start with the circulation integral: ∫E*ds = 0. This is a fundamental experimental observation. Then invoke Stokes' theorem to show that the curl of E must always be zero since the theorem applies to all possible closed paths.

Then invoke the fact that, in consequencxe of curl E = 0 there exists a potential function V such that E = - grad V.
 

FAQ: Past exam question about electrostatic field and potential

What is an electrostatic field?

An electrostatic field is a type of force field that is created by stationary electric charges. It is responsible for the attraction or repulsion of charged particles and is described by the strength and direction of the force it exerts.

What is electric potential?

Electric potential is a measure of the potential energy per unit charge at a specific point in an electric field. It is measured in volts and represents the amount of work needed to move a unit of electric charge from one point to another.

How is the electric potential related to the electric field?

The electric potential is directly related to the electric field through the equation V = E * d, where V is the potential, E is the electric field strength, and d is the distance between the two points. This means that the electric field is the gradient of the electric potential.

What is the difference between electric field and electric potential?

The electric field is a vector quantity that describes the force exerted on a charged particle, while the electric potential is a scalar quantity that describes the energy per unit charge at a specific point in the field. In other words, the electric field describes the strength and direction of the force, while the electric potential describes the amount of work needed to move a charged particle to a specific point.

How is the electrostatic potential energy calculated?

The electrostatic potential energy is calculated using the equation U = q * V, where U is the potential energy, q is the charge of the particle, and V is the electric potential at a specific point. This equation represents the work done in moving a charged particle from infinity to a specific point in the electric field.

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