### SAT Physics Electric Potential - Potential Of Uniform Fields

##
** SAT Physics Electric Potential - Potential Of Uniform Fields**

**POTENTIAL OF UNIFORM FIELDS**

Uniform electric fields are a property of equal and oppositely charged parallel plates. Since the electric field between these plates is uniform, the electric potential is evenly distributed in the space between the plates. Figure 11.1 shows how the electric potential associated with a set of 6-volt plates is commonly visualized.

**Figure 11.1. Electric potential for uniform fields**

Since the negative plate is low potential, it is often set as the zero point to simplify problems. By definition, the positive plate is considered to be the high potential plate. In this figure, it is set as 6 volts. By definition, the negative plate is the low potential plate. Here it is set as 0 volts. Electric potential is similar to height h in a mechanics problem, where the surface of Earth is the zero point and each meter of height is equally spaced and parallel to Earth.

The magnitude of the electric potential, V, at a location in a uniform electric field can be determined with the following formula.

V=Ed

In this formula distance, d, is measured from a location where the potential is equal to zero to the point in the field where potential is to be solved.Although charged plates have a uniform electric field between them, the value of the electric potential at each plate is different. In Figure 11.1, the positive plate has a potential of 6 volts and the negative plate has a potential of 0 volts. This difference is known as a

**potential difference**, ΔV. Its value is found by subtracting the two potentials: ΔV =6-0 = 6. The potential difference of charged plates can also be determined with a modified version of the previous equation.

ΔV=EΔd

The electric field, E, of charged plates is uniform and does not change. The distance Ad is the space between the plates.The electric potential can be viewed as lines that are perpendicular to the electric field and equally spaced. These lines are known as

**equipotential lines**. Every point on a particular equipotential line has the same equal potential. In Figure 11.2, a point P, a positive charge, and a negative charge are all shown at a location where their electric potentials are 4 volts relative to the negative plate. They are all on the same equipotential line.

**Figure 11.2.**Electric potential

Some problems will ask for the electric potential of a point or charged object located between charged plates. This is calculated with the same equation used to find the potential of the plates themselves, V = Ed. However, the distance, d, is measured from the zero location (usu¬ally the negative plate) to the point or charged object, as shown in Figure 11.2.

**Electric Potential of a Uniform Field**

Two charged plates with a 20 newton per coulomb electric field are separated by a distance of 10 centimeters. A proton is located at the midpoint between the plates.

**(A)**Determine the potential difference between the charged plates.

**WHAT'S THE TRICK?**

To find the potential difference of the charged plates, use the formula. Remember to change the distance to meters.

ΔV= EΔd

ΔV = (20 N/C)(0.10 m) = 2 V

ΔV = (20 N/C)(0.10 m) = 2 V

**(B)**Determine the potential acting on the proton.

**WHAT'S THE TRICK?**

You need to find the potential at the point where the proton is located. Since the proton is at the midpoint between the plates, the distance (in meters) is half the distance between the plates.

V= Ed

V = (20 N/C)(0.05 m) = 1 V

V = (20 N/C)(0.05 m) = 1 V

**POTENTIAL OF POINT CHARGES**

The electric potential of point charges is visualized in an entirely different manner and is solved using an entirely different equation than that of uniform fields. The electric field of point charges is radially oriented pointing away from positive charges, and radially oriented toward negative charges. The magnitude of the field has a maximum value at the surface of the charge and becomes weaker with the inverse square of the distance from the center of the charge. It has zero strength at infinity. Although electric potential is not a vector and has no direction, its magnitude follows a similar pattern to that of the electric field surrounding a point charge. Potential has its highest magnitude at the surface of a charge and diminishes to zero at infinity. The lines of equal potential (equipotential lines) are perpendicular to the field and form concentric circles around the charge. An example is shown in Figure 11.3 for a positive charge with a 6-volt potential at its surface.

**Figure 11.3.**Electric potential of point charges

The equation for potential is very similar to the equation for the electric field. However, potential is a scalar quantity while the electric field is a vector.

**Electric Potential of Several Point Charges**

If a problem consists of several point charges surrounding a point P, then merely add together the electric potentials of the individual charges. To find the total potential, simply sum the individual electric potentials.

**Electric Potential of Point Charges**

A +4 coulomb charge is located 4 meters to the left of the origin. A -4 coulomb charge is located 4 meters to the right of the origin. Determine the electric potential at point P located at the origin.

**WHAT'S THE TRICK?**

The charges are spherical. Use the potential equation for point charges.

Since there are two charges, add them. The sign on the charges is important. However, the sign on the distance from the origin is not.

**ELECTRIC POTENTIAL ENERGY**

Once the electric potential at a point in space is determined, any charge q can be inserted at that point and the electric potential energy, U

_{E}, can be determined. Simply multiply the electric potential, V, at a point in space by the charge, q, located at that point.

U

The relationship between electric potential and electric potential energy is similar to that between electric field and electric force. A point in space will have a specific electric field value, E, and a specific electric potential value, V. When a charge, q, is placed at a point in space, the electric field creates a force, F_{E}= qV_{E}, on the charge. The electric potential can be used to determine its electric potential energy, U

_{E}.

F

Whether the electric potential is due to charged plates, a single point charge, or several point charges, the equation to find electric potential energy is the same. In Figure 11.4(a), a point charge q is located in the uniform field of charged plates. In Figure 11.4(b), a point charge q_{E}= qE and U_{E}= qV_{2}is located in the electric field created by point charge q

_{1}

**Figure 11.4.**Electric potential energy

You can substitute the equations for electric potential, V, into the equations found in Figure 11.4(a) and Figure 11.4(b) to create alternate equations for electric potential energy.

_{B}can be thought of as the potential to move charges. Electric potential, V, is directly proportional to electric potential energy. In an electrical circuit or in problems involving the motion of charges, electric potential can be thought of as an electrical pressure that exists at a point in space or in a circuit. Any charge located at that point will have the energy needed to move. Electric potential is also commonly called voltage. High voltage is a high potential for charges to move and thus a greater chance of receiving an electric shock.

Thanks for sharing such a nice article. It is really useful to me and all people. One thing in my mind came while reading that it is not wasting of time. currency exchange app shopify , currency converter box free online , best shopify apps to boost sales in 2019

ReplyDeleteI guess you are a smart cookie because of your knowledge and insight. The articles brings some advice. I learn more from them. Please update more posts. I usually read them. Thank you very much.sale discount app on Shopify , Product discount master , best shopify free apps to boost sales in 2019

ReplyDeleteYou may need to for a board to aid the plan, assessment, determination and conceivably money related help of your new band uniforms. check this out

ReplyDeleteIn the event that you can't discover a suit with a coat and skirt or pants to fit and praise your body shape, you could generally have a go at purchasing the skirt or pants and coat independently as long as you pick an impartial shading like dark or naval force that is anything but difficult to coordinate. anaya lawn unstitched

ReplyDeleteA similar texture pores that help keep water from infiltrating inside a jacket, permit sweat particles to get away and at last keep your hotter. beverly hills cop jacket

ReplyDeleteIt is currently his responsibility to transfer to the maker that this is actually how you need your band uniforms fabricated. It is additionally astute to take some photographs of the uniform for your records as of now. distressed leather jacket

ReplyDeleteYou have a genuine capacity to compose a substance that is useful for us. You have shared an amazing post about test and tag services brisbane.Much obliged to you for your endeavors in sharing such information with us.

ReplyDeleteI really want to thank the author for such a nice blog that helped me to understand why testing and tagging Melbourne is important. thanks for sharin

ReplyDeleteA very delightful article that you have shared here about Electrical Outlet Box. Your blog is a valuable and engaging article for us, and also I will share it with my companions who need this info. Thankful to you for sharing an article like this.

ReplyDeleteI’m genuinely impressed with your knowledge. You have shared good knowledge by this blog. It was a really attractive blog. Please keep sharing your post with us.Rent Bidwell bridge paving machinery in USA.

ReplyDeleteThis article provided me with a wealth of information aboutelectrical test and tag. The article is both educational and helpful. Thank you for providing this information. Keep up the good work.

ReplyDeleteThe information in the post you posted here is useful because it contains some of the best information available. Thanks for sharing it. Keep up the good work Safety Goggles Online

ReplyDeleteWow, What an Excellent post. I really found this to much informative. It is what I was searching for. I would like to suggest you that please keep sharing such type of info.

ReplyDeletesite.tile and stone adhesiveThanks for sharing useful information. We are the reputed natural stone suppliers Melbourne offering luxurious natural stones & stone benchtops Melbourne at affordable price.

ReplyDelete