WEEK

We are going to explore electricity and electronics.

GOALS:

• Develop some intuition and understanding of current and resistance.
• Water Module (see class handout and class demo)
• Learn to use a multimeter to measure current.
• Measure the voltage and the current of a battery. (See circuit below.)
• Measure the voltage and the current of a power supply and resistor combinations. (See circuit handout in lab).
• Explore the features of LED's, light emitting diodes.

Current is the flow of electric charge. A resistor restricts the flow in a manner that is roughly the same as water flow is restricted by a narrow pipe. The equation that defines the relationship between voltage V, current I and resitance R is called Ohm's law.

V = I R

It simple tells us that the greater the resistance the smaller the current.

To measure current we set or multimeter to the current settings by turning the dial. We must also move the probes to other locations. The black probe remains in the com location but the red probe is shifted to either of the other two holes. This will be explained in detail in the lab.

When measuring current we must remember that whatever current we want to measure, it must pass through the meter. The key word is through. Be sure you understand what current will pass through a meter when it is hooked into a circuit.

Consider the following circuit

This circuit may give a surprising result. It helps us understand the importance of understanding how current is measured.

This weeks questions are based on the goals above.

QUIZ *******

QUIZ *******

In order to receive a grade of A you must successfully complete the lab portion of the course, read prelab material, and pass the lab quiz. In order to pass you must get 75% of the questions correct.

In order to receive a grade of B you must successfully complete the lab portion of the course. The quiz is optional. For fun feel free to try the quiz.

You are not allowed to consult with other students while taking the quiz. You will be given a limited time period to complete the quiz. You may refer to any written material.

You may take the quiz at any time during the week but only once.

The quiz will be available starting on the day you cover the material and ending one week later.

If you have troubles please discuss the difficulties with DRG.

You are not allowed to consult with other students while taking the quiz. The quiz will be available at least from lab until following lab. You will be given 30 minutes to complete the quiz and you may refer to any written material.