1 Current, Voltage & Resistance Conductors & Insulators

2 Energy in a Circuit... is similar to water through pipes We will learn how to measure the energy in a circuit and how... are related. and

3 1.5 V 0.0 V The potential difference (voltage) is 1.5 V. Potential Energy (height) To Lower Energy Potential Difference is a measure of “potential difference.” 1.5 Meters The unit for voltage is volts (V)

4 Higher Potential energy (height) To Lower Energy Potential Difference Greater Potential Difference 3.0 V 0.0 V The potential difference (voltage) is 3.0 V. The higher the energy, the greater the voltage (potential difference). 3.0 Meters

5 = 1.5 volts 3.0V ?V Is the voltage the same in A, C and D cell batteries? Let’s look.

6 rate is the rate that the electricity moves. + How fast is this water coming out? How fast (speed) is the electricity flowing through these wires? CURRENT (I) is measured in Amperes (Amps).

7 Flows in 1 direction Flows 2 directions Alternating Current (AC) Direct Current (DC) Current goes back and forth about 60 times per second. Example: Wall socket is 120v Only Batteries – AAA, AA, C, D Cell These are all 1.5V each, but the difference in size means they should last longer period of time.

8 The smaller pipe would have greater resistance to the flow because it has a smaller diameter and not as much water goes through it. is anything that opposes the flow of electrons or prevents electricity from moving. Back to the water analogy…Which of the pipes below would prevent water from traveling the fastest? Pipe 1: Smaller Diameter Pipe Pipe 2: Larger Diameter Pipe Measured in units called Ohms ( ). 

9 Which of the following do you think would be most resistant to electrical current? Why? Plastic Rubber Glass These materials DON’T allow current to move easily through them. Therefore they are called They have a strong resistance to the flow of electrical current.

10 These materials allow electrical charge (current) to move easily through them. They have little resistance to the flow of electrical current. Which of the following do you think would be the least resistant to electrical current? Why? Plastic Rubber Glass Therefore they are called

11 Resistance Current Voltage How Fast? How much? How much is it slowed down? Match the word on the left to the phrase on the right. (R) in Ohms  (I) in Amps (V) in Volts