01 current, resistance, voltage, & ohm's law

Current

It is the amount of charge flowing on a wire at a certain area per unit

Ampere

SI unit of current

Electric Field

Current:

The movement of charges is affected by the presence of ___ in the materials. For conductors, free electrons are moving in random directions, but on the introduction of steady ___, the charges will experience a force.

1. Conventional Flow

2. Electron Flow

2 Types of Current Flows

Conventional Current

Current Flow:

It assumes that current flows out from the positive side of the battery, through the circuit, back to the negative side

Electron Flow

Current Flow:

It assumes that current flows out from the negative side of the battery, through the circuit, back to the positive side

1. Direct Current

2. Alternating Current

2 Types of Electric Currents

Direct Current

Electric Current:

It flows in one direction

Alternating Current

Electric Current:

It changes direction periodically

Resistance

It describes the opposition of the material to the flow of charge carriers

Ohm

SI unit of resistance

Resistor

It is any device that contributes appreciable resistance to the flow of charge

Resistivity

It represents the ability of a material to oppose the motion of charge carriers

Resistance on the wire

Resistance:

It varies directly with the length and the resistivity, and inversely with the cross-sectional area of the given material

Potential Difference

Voltage is also known as ?

Voltage

It is the required energy to move the unit charge from one point to another

Volt

SI unit of voltage

Electromotive Force

It is the energy supply to the charge by a battery cell

Electromotive Force

It is the maximum potential difference between two terminal of a battery when no current is flowing from the source

Volt

SI unit of electromotive force

Georg Simon Ohm (1827)

He discovered some laws relating to the strength of a current in a wire

Ohm’s Law

This law states that there is a direct proportionality between current and voltage, but inversely proportional between current and resistance