Reading Quiz 5 Key

Reading Quiz 4 Key

Due before class Wednesday, Jun 27th

Physics 106, Summer 2012


Reading: Chapter 18 Sec 1-4

Did you complete the reading assignment?

Yes
No

Did you complete the entire quiz or spend at least 15 minutes working on this quiz and the attached links?
Yes
No

KEY CONCEPTS:

1) Resistance is a measure of its opposition to the passage of a steady electric current.

2) Current is the flow of electric charge.

3) Voltage, resistance, and current are related to each other through Ohm's Law.

The last quiz talked about capacitance and how charge can be stored. In order for this to happen charge has to move. This is called current. The more charges moving and the higher the speed at which they move, the higher the current. Resistance is what slows down or decreases the current.

Conventional current is the flow of positive charge in a circuit. What flows through an electrical circuit?

Protons
Electrons
Both protons and electrons

Exercise 1

Try this link: http://www.mste.uiuc.edu/murphy/Resistance/default.html

Increase and decrease the values of voltage and resistance and observe what happens. Think of a traffic jam, and how the applet reminds you of  a traffic jam.

What is the current like?

The number of cars on the road.
How fast the cars are moving on the road.
How many cars get through a certain stretch of road in a certain amount of time.
The number of lanes the cars can travel in stretch of road at a given time.

What is the resistance like?

The number of cars on the road.
How fast the cars are moving on the road.
How many cars get through a certain.
The number of lanes the cars can travel in stretch of road at a given time.

What is the voltage like?

The number of cars on the road.
How fast the cars are moving on the road.
How many cars get through a certain.
The number of lanes the cars can travel in stretch of road at a given time.

What happens when the resistance is increased greatly?

Exercise 2

Go to the following applet and click the 'Run Now' button: http://phet.colorado.edu/simulations/sims.php?sim=Ohms_Law

Increase and decrease the voltage and resistance of the simple circuit using the sliders at the top right. You will see values for voltage, resistance, and current as well as watching the size of the variables in the equation change size and the size of the arrows increase or decrease to help you see relative values.

As you increase voltage, what happens to the current?

It increases
It decreases

As you increase resistance, what happens to the current?

It increases
It decreases

Why does current flow in a circuit?

The pendulum in pendulum court has a warning on it that reads: "Warning: 10,000 Ohms". Should this warning scare you from touching the pendulum? Why or Why not?


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Was there anything that you didn't understand in the reading assignment?  What was confusing to you?


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