Designing the Ammeter
Your table has been asked to design a circuit to determine the current
through the light bulb in the circuit below.
Your boss has a few ideas but still has some questions. She's asked
each group at your table to look at part of the problem. Click below to
see your group's assignment:
Group 1:
One possible way to measure the current through the bulb is to hook
up an ammeter in parallel with the bulb (as shown below):
The questions your boss has about this design are:
-
How does the current through the meter compare to the current through the
bulb?
-
Is this a good way to measure the current through the light bulb? Why or
why not?
Once your group is satisfied with the answers to these questions, confer
with the other groups at your table to prepare the final
report to your boss.
Group 2:
One possible way to measure the current through the bulb is to hook
up an ammeter in series with the bulb (as shown below):
The questions your boss has about this design are:
-
How does the current through the meter compare to the current through the
bulb?
-
Is this a good way to measure the current through the light bulb? Why or
why not?
Once your group is satisfied with the answers to these questions, confer
with the other groups at your table to prepare the final
report to your boss.
Group 3:
One concern your boss has about adding a meter to the circuit might significantly
change the behavior of the circuit. Look at the two circuits below:
The questions your boss has are:
-
What effect does adding the meter to the circuit have?
-
How can the meter be designed so that this effect is minimized?
Once your group is satisfied with the answers to these questions, confer
with the other groups at your table to prepare the final
report to your boss.
The Final Report
Write a memo to your boss that explains how the ammeter should used to
measure the current through the bulb. Make sure that your memo addresses
all of the her questions.