Electrical Quantity  Description  Units  Water Analogy 
Voltage or Potential Difference 
A measure of the Energy difference per unit charge between two points in a circuit. 
Volts (V)  Water Pressure 
Current  A measure of the flow of charge in a circuit. 
Amperes (A)  Amount of water flowing 
Resistance  A measure of how difficult it is for current to flow in a circuit. 
Ohms (Ω)  A measure of how difficult it is for water to flow in a pipe. 
Power Macintosh  wires 
Lab Pro  clips to hold wires 
Logger Pro 2.1  light bulb (6.3 V) 
Adjustable 5volt DC power supply  two resistors (about 10 and 50 Ω) 
Vernier Current & Voltage Probe System 
Slope of regression line (V/A) 
Yintercept of regression line (V) 

Resistor Ω  
Resistor Ω  
Light bulb (first 3 pts)  
Light bulb (last 10 pts) 