φfizikzauglom

10TH GRADE · ELECTROSTATICS

Potential and voltage

Field work, potential energy, potential and potential difference.

24 minutes16 theory cards
Open interactive lesson

LESSON MATERIAL

Basic Concepts

2

Potential

Energy characteristics of the electric field at a selected point.

The potential is equal to the potential energy of a unit positive charge; its zero level is chosen according to the conditions of the problem.

Voltage

The potential difference between two points is equal to the work done by the field on a unit charge.

Voltage measures how much energy a unit of charge gains or loses when moving between two points.

LESSON MATERIAL

Physical quantities

5

Electric potential

φ\varphi

Potential energy of a unit positive charge.

Unit: volt · V\mathrm{V}

Potential charge energy

WpW_{\text{p}}

The energy of a charge due to its position in an electric field.

Unit: joule · Dzh\mathrm{Dzh}

Electrical voltage

UU

Electric field work per unit transferred charge.

Unit: volt · V\mathrm{V}

Electric field work

AA

The energy transferred by the field to the charge during movement.

Unit: joule · Dzh\mathrm{Dzh}

Distance between plates

dd

The distance along a uniform field between the points under consideration.

Unit: meter · m\mathrm{m}

LESSON MATERIAL

Lesson formulas

9

Determination of potential

φ=Wpq\varphi=\frac{W_{\text{p}}}{q}

The potential is equal to the potential energy of a unit positive charge.

Volt definition

1 V=1 DzhKl1\,\mathrm{V}=1\,\frac{\mathrm{Dzh}}{\mathrm{Kl}}

One volt is equal to one joule per coulomb.

Voltage detection

U=AqU=\frac{A}{q}

The voltage is equal to the work done by the field to transfer a unit charge.

Point charge potential

φ=kqεr\varphi=k\frac{q}{\varepsilon r}

The potential of a point charge decreases inversely with distance.

Work of a uniform field

A=qEdA=qEd

The work of a uniform field is equal to the product of charge, intensity and displacement along the field.

Uniform field strength

E=UdE=\frac{U}{d}

The tension between parallel plates is equal to the voltage divided by the distance.

Energy of two point charges

Wp=kq1q2εrW_{\text{p}}=k\frac{q_1q_2}{\varepsilon r}

The potential energy of a pair of charges depends on the charges, distance and environment.

Superposition of potentials

φ=φ1+φ2+…\varphi=\varphi_1+\varphi_2+\ldots

The potential of several sources is equal to the algebraic sum of the individual potentials.

Coulomb in ampere and second

1 Kl=1 A⋅s1\,\mathrm{Kl}=1\,\mathrm{A}\cdot\mathrm{s}

One pendant passes through a section in one second at a current of one ampere.

DIRECTORY

Related formulas

Electrical voltageU · BPotentialφ · BWorkA · JDistance and pathS, l · m

PRACTICE

Tasks on the topic

Electrostatics10 class · 12 problems