Electricity 1: Electrical Quantities and Ohm's Law

What is current?

the flow of electrons through a conductor

when dealing with flown rate there must be a unit of measurement, what is the unit?

The unit for a quantity of electron flow is coulomb

1 coulomb is equal to _____.

6.28 x 10^18 electrons

For practical purposes electrical current is measured in units called ____.

Amperes or amps

1 amp equals what?

1 amp = the flow rate of 1 coulomb past 1 point in one second.

what are volts?

The electrical pressure that causes electrons to flow

What is the force that causes electrons to flow through a conductor?

Electromotive Force/EMF

What is the difference between voltage and volts?

Voltage is the electrical pressure that causes electrons to flow. Volts are the unit of measurement.

What is the symbol for current?

the letter I

What is the symbol for voltage?

The letter E

What is the symbol for volts?

the letter V

What is resistance?

the property of a conductor that tends to restrict the flow of electrons

What is the unit for resistance?

Ohms

What is the symbol for Resistance/Ohms?

The letter R or the greek letter omega Ω

What is Ohm's Law

Current through a conductor between two points is directly proportional to the voltage across two points. It takes 1 volt to push 1 amp through 1 Ohm

Simply put Ohm's Law is?

E (volts) = I (amp) x R (resistance). E=IxR

What is power?

The rate of doing work

How is power measured in an electrical circuit?

In Watts

How is power measured in a mechanical device?

In horsepower

1 hp = 550 ft-lb per second

How is 1 watt of power expelled?

When 1 volt of electrical pressure moves 1 amp of current through a circuit.

1 watt is equivalent to how many horsepowers?

0.00134 hp

1 horsepower is equivalent to how many Watts?

746 Watts

Power consumed by an electrical circuit is ____.

Additive

Simply put Watts is?

Watts = E(volts) x I(amps)

W=ExI

What are the factors (4) affecting resistance

1. type of conductor material

2. the length of the conductor material

3. Cross-sectional area of the conductor

4. Temperature of the material

Resistance is directly proportional to the length of ____.

The conductor. The double the length, the double the resistance.

As temperature of the conductor increases...

the resistance increases. Known, as the temperature coefficient of resistance

The cross-sectional area is...

inversely proportional. Meaning that double the cross-sectional area = 1/2 the resistance