At-Home Activities

1. With parental permission, dismantle a simple flashlight. Try to identify the four basic parts of a simple circuit in the flashlight. What components are different from the circuit used in Investigation 10.1?
2. If you have more than one flashlight at home, examine all of them and identify the differences. Why might they be different?
3. If you have a bicycle that has a lighting system, examine it to see how the different parts operate. Is there a battery, or are there other means of producing the electrical energy needed to light the bulbs? Compare this system to the flashlight(s) you examined earlier.

WARNING: DO NOT INVESTIGATE ANY APPLIANCE OR ELECTRICAL DEVICE THAT OPERATES ON VOLTAGES HIGHER THAN 12 V.

Draw a schematic circuit diagram for each of the flashlights (or the bicycle lighting system) you examined in the At-Home activity for section 10.1 (above).

Record the electric potential (voltage) of various sources of electrical energy in your home. Suggest reasons why the particular voltage has been selected for each application.

Inquire among family members, relatives and acquaintances about careers in physics-related, engineering-related and technology-related fields of employment.

Visit your local hardware or electronics store and make a list of all the batteries sold there. (Do not list the 1.5-V dry cells.) Identify the voltage of each battery, and from that determine the number of dry cells inside each battery to produce the voltage of the battery.

Try to estimate how many dry cells your family discards each year. Then estimate how many families there are in your school, including the teaching staff and all the support staff. From this information, make a reasonable estimate of the total number of dry cells and batteries that are discarded by the entire school population each year. Compare your estimates with those of other class members and use the data to complete the assignment in this lesson.

Make a list of simple electrical devices and appliances in your home that consist of a single electrical load that converts electrical energy into heat or light energy.

Calculate the electrical resistance of light bulbs in the flashlights you use at home. The current ratings of flashlight bulbs are usually printed on the metal section above the screw thread. By checking the voltage of the dry cell or battery used in the flashlight, you will be able to determine the voltage drop across the bulb.

Examine various sets of decorative lights you may have in your home. How many have series circuits and how many have parallel circuits? What is the fastest way to check whether a set of lights is connected in series or parallel?

Identify all the appliances and devices that have multiple electrical loads that are all connected to the same device. Determine, by operating the appliance and device in the way specified in the user's operating manual, how many of the loads on each appliance are operated simultaneously, and how some can be operated independently. For each appliance, describe what has to be done to control the electrical loads that are operated independently, and explain how the control devices operate.

The Chapter Review (pp. 328-329) in your textbook lists all the Key Expectations you have covered in the chapter and identifies the specific lessons in which the knowledge and skills have been developed.

You can use the Key Expectations list to help you create a personal study guide in preparation for an end-of-chapter test:

1. Copy down the list of learning expectations from your textbook.
2. For each learning expectation, locate the appropriate lesson(s) in the unit where the expectation was covered. These are identified in parentheses at the end of each expectation (e.g., 10.2).
3. Flip to the appropriate lesson(s) for each expectation and make study notes of the key ideas or skills you learned.