# Electric field with reference to voltage

• Angello90
In summary, the conversation discusses the relationship between electric potential and electric field, specifically in the context of the equation E=-∇V. It is clarified that the negative sign in the equation represents the change in potential over distance, and it is explained that the field points towards the negative side and away from the positive. The concept of a field being "emitted" is also addressed.
Angello90
If E=-∇V, does it mean that negative voltage emits positive electric field, and positive v negative ef?

It's basically a matter of definition.
I think you can look at it this way: The field between a positive plate and a negative plate is said to be directed towards the negative plate (the direction in which a positive charge would move) but the positive plate has a positive potential with respect to the negative plate i.e. voltage increases in the opposite direction to the direction of the force on a positive charge.

you see I have this question where youre give an equation for potential deference of 10-5z^2, so E= -10z right?, anyway there is a field on one side of the slab (slab is the material with a charge) and it asks about EF on both sides, ie what is EF on right hand side and left hand side. As a hint there is "watch the sign" statement. So I am really confused

Angello90 said:
If E=-∇V, does it mean that negative voltage emits positive electric field, and positive v negative ef?

That is not what the Grad means! It is the CHANGE in potential over a distance, i.e. a gradient. In 1 dimension, it is E = -dV/dx.

Zz.

Yeah and d(10-5z^2)/dz=-10z, am I correct?

Uh?

If you want a simple explanation for the sign, the field points towards the negative side and away from the positive. i.e. a negative slope as distance towards the positive increases - hence the negative sign.
Note. A field isn't "emitted".

Ok thanks a lot sophiecentaur, and yeah i know field isn't emitted, that's why i used "emitted" not emmited;) thanks guys

Angello90 said:
Ok thanks a lot sophiecentaur, and yeah i know field isn't emitted, that's why i used "emitted" not emmited;) thanks guys

It was terminology I was referring to - not spelling

## What is an electric field?

An electric field is a physical field that surrounds an electrically charged particle and exerts a force on other charged particles within its proximity.

## How is electric field related to voltage?

Electric field and voltage are closely related. Voltage is the measure of the potential difference between two points in an electric field. It represents the amount of energy required to move a charged particle from one point to another within the field.

## How is electric field strength measured?

The strength of an electric field is measured by the force exerted on a unit charge (in Coulombs) placed at a specific point in the field. It is represented by the unit Newtons per Coulomb (N/C).

## What is the formula for calculating electric field strength?

The formula for calculating electric field strength is E = V/d, where E is the electric field strength in N/C, V is the voltage in volts, and d is the distance between the two points in meters.

## How does the direction of the electric field relate to voltage?

The direction of the electric field is always from the higher voltage point to the lower voltage point. This is because the electric field always moves in the direction of decreasing voltage, similar to how water flows from a higher to lower elevation.

• Electromagnetism
Replies
4
Views
1K
• Electromagnetism
Replies
2
Views
975
• Electromagnetism
Replies
21
Views
2K
• Electromagnetism
Replies
11
Views
375
• Electromagnetism
Replies
3
Views
781
• Electromagnetism
Replies
2
Views
857
• Electromagnetism
Replies
14
Views
1K
• Electromagnetism
Replies
3
Views
706
• Electromagnetism
Replies
6
Views
364
• Electromagnetism
Replies
1
Views
318