Section 2: Current

Explain the relationship among voltage, current and resistance in a simple series circuit.

I can explain Ohm’s Law. I can calculate voltage, current and

resistance using Ohm’s Law.

Ohm’s Law explains the relationship between voltage (V or E), current (I) and resistance (R)

Used by electricians, automotive technicians, stereo installers, etc.

It is the push or pressure behind current flow through a circuit, and is measured in (V) volts. 

Current refers to the quantity/volume of electrical flow. Measured in Amps (A)

 Resistance to the flow of the current. Measured in Ohms

1.  Assuming the resistance does not change:As voltage increases, current increases.As voltage decreases, current decreases.

2.  Assuming the voltage does not change:As resistance increases, current decreases.As resistance decreases, current increases.

V = I x R

I = V R

R = V I

Battery voltage is 12V Current? Resistance 2 Ohm

VV

Voltage is 12V Current is 4 Amps Resistance in Ohms ?

V

V

Multi meters/ DVOM

Why do we need resistors?

To decrease the amount of voltage applied to a component

The value of the resistor is marked on the body using colored rings.

What is Voltage? What is Current? What is Resistance? Calculations on worksheet