Kirchoff’s Rules - Capacitance - Electric Charge - Electric Potential

Capacitor

- a device used to store electrical charge

- consists of two conductive plates separated by a dielectric material.

- measured in Farads (F)

ε0 = 8.85 x 10-12 F/m

permittivity (electric constant)

Kirchhoff's Rules

- named after German physicist Gustav Kirchhoff

- a systematic way of solving multi-loop circuits

JUNCTION

- "The sum of the currents at a junction is equal to zero."

- Current In = Current out

LOOP RULE

"The sum of the potential differences around a closed loop equals zero."

-IR

If transverse (direction of the loop)

through a resistor is the same

direction as the current, the change in

potential (V = IR) across the resistor is?

+IR

If transverse through a resistor is

opposite to that of current, the

change in potential across the resistor

is?

-E

If transverse enters the + terminal

and exits the - negative terminal of

an emf source, the change in

potential across the terminal is?

+E

If transverse enters the - terminal

and exits the + positive terminal of

an emf source, the change in

potential across the resistor is ?

ELECTRIC CHARGE

- determines the electric interaction and magnetic interaction between subatomic particles and other charged particles

- affected by electromagnetism

Quantization

coming in discrete units of the

elementary charge which is the charge of a single

proton or electron.

CHARGING

- the process of transferring electrons from one object to another.

Charging by Rubbing

- "ripping off" of electron(s) from the body with a weaker electron hold.

- "ripped off" electrons are then transferred to the other body.

Triboelectric

- refers to the phenomenon where certain materials become electrically charged after they come into contact with another material and then are separated.

- occurs due to the transfer of electrons between materials, resulting in one material becoming positively charged and the other negatively charged.

Triboelectric Charging

- if you rub two materials against each other, the one nearer the top will receive net positive charge and the oher a net negative charge

- more intense rubbing = greater charge transfer

Charging By Conduction

- transferring electric charge between objects through direct physical contact, where a charged object touches a neutral one, causing electrons (or charge) to flow until both objects share the same type of net charge (positive or negative)

Charging by Induction

- to electrify a neutral object without direct contact, using a nearby charged object to redistribute the neutral object's charges, creating temporary polarization and allowing for permanent charging if a path

Induced charge

is the charge that is redistributed within an object when it is placed in an electric field or near a charged object, but without direct contact.

Grounding

- refers to connecting a device, circuit, or electrical system to the Earth (or another large conductive object) to safely allow excess electric charge to flow away.

ELECTRIC POTENTIAL ENERGY (U)

-Work is required to overcome the repulsion between the two positive charges to hold them together in this way

- Amount of work gives the system of two charges

Electric Potential

- is the amount of electric potential energy per unit charge.

- equivalent to the amount of work needed to move a charge from one reference point to another

• want charges to be moving

electro statistics

study of charges at rest and the forces, fields, and potentials they create, focusing on interactions like attraction and repulsion without magnetic complications

9 × 10^9 Nm²/C²

Coulomb’s contant (k)

10^-6

Mew coulomb is 10 raised to what?