Ohms Law

Students Prepare :Abdullah Al Asfour .Samer Al Gamdi .How voltage, current and resistance relate ?How voltage, current and resistance relate ?

By Ohms Law ..Introduction :

Voltage and Current analogy :

Current :- It is the rate of flow of charge .

- The symbol is I .

- It is measured in amps (ampere) A .(for example I=5 A or I=5 amps) .

- Current cannot flow without voltage .Current :

Voltage :- It is a measure of the energy carried by the charge .

- It attempts to make a current flow .

- The Symbol is : V or E .

- It is described as a push of the electric current .

- It is measured in Volts (V=1.5v) .Voltage :Voltage is supplied by ..

Resistance :- It is the impedance of the current flow .

- The symbol is R .

- All electrical equipment has an internal resistance .

- It is measured in ohms .Resistance :

Current, Voltage and Resistance :

Georg Simon Ohm(16 March 1789 6 July 1854)

Ohm's Law:- To make a current flow through a resistance there must be a voltage across that resistance .

- Ohm's law shows the relationship between the voltage (V), current (I) and resistance (R) .

- V = I * R - I = V / R - R = V / I .

How to decrease the flow rate without change the pressure ?

How to increase the flow rate without change the resistance ?

How to decrease the pressure without change the flow rate ?

The relationship between Current, Voltage and Resistance :

Examples ..E1 : Find the voltage ?

E2 : Find the lamp resistor ?

E3 : Find the current ?

Exercises ..Exercises :Q1 : A 3 V is applied across a 6 ohm resistor, what is the current ?

Q2 : lamp connected to a 6 V battery passes a current of 60 mA, what is the lamp's resistance ?

Q3 : A 1.2 k ohm resistor passes a current of 0.2 A, what is the voltage across it ? Exercises :A1 :

A2 :

A3 :Summery- Voltage measured in volts, symbolized by the letters E or V .

- Current measured in amps, symbolized by the letter I .

- Resistance measured in ohms, symbolized by the letter R .

- Ohms Law : V = I * R - I = V / R - R = V / I .Any Questions ?Recommended websites :- http://www.the12volt.com/ohm/ohmslaw.asp .

- http://www.allaboutcircuits.com/vol_1/chpt_2/1.html .

- http://www.physics.uoguelph.ca/tutorials/ohm/Q.ohm.intro.html .Thank YouFor Attention ..