# 9/28 Group Activity

• Design three questions related to electrical circuits, one each representing easy, intermediate, and difficult levels. These questions should represent those which you think might appear on an exam and would like the answer to beforehand.
• Some of these will appear on the midterm exam!
• You will be rated on appropriateness and originality.
• Please remember to list the participating members of the group on your markerboard -- initials are OK.

### Proposed Questions:

These have been copied from the markerboards with very slight editing.

New Generation

• Easy:
According to the circuit shown below, will this light the bulb? Why?
[Drawing of bulb with base touching bottom of battery and contact wired to other end of battery.]
• Medium:
A current of 3 amps flows through a resistor with a voltage of 24 volts. What is the resistance?
• Hard:
Two 1.5 V batteries in a flashlight with resistance of 2 ohm were left running for 3 hours. How much power would be left?
Ohms
• Easy:
How do you lower current associated with power distribution?
• Medium:
Why does ac come out of the wall and not dc?
• Hard:
Explain the difference between voltage and voltage difference.
Whatever
• Easy:
What is the ultimate goal of this class?
• Medium:
Using the circuit below, what is the current through the 20 ohm resistance?
[Drawing of 20 and 25 ohm resistors in series with 1.5 V battery.]
• Hard:
How do you determine the voltage difference of a 11 ohm resistor?
[Drawing of an 11 ohm resistor connected to a 6 V battery with 1 ohm internal resistance.]
Voltage
• Easy:
Which resistor has the most current flowing throught it? R1>R2>R3
[Drawing showing three resistors, R1, R2, and R3, connected in parallel to battery.]
• Medium:
Water flows from high to low pressure [was low to high in original statement]; if you want to reverse this process, how would you do it?
• Hard:
When going from low resistance to high resistance, how does the bottleneck theory play a role?
Threesome
• Explain all the similarities and differences between series and parallel circuits.
• Why is the resistance of a cylinder proportional to the length, but inversely proportional to the cross-sectional area?
• Why is ac current preferable to dc current in reference to household wiring?
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Comments, suggestions, or requests to ghw@udel.edu.