Problem Set 7
Due: See website for due dates
Chapter 27: Circuits
Exercises & Problems: 1, 26 (challenging), 33, 39, 45, 61, 63, 72
Question A
Explain why an ideal ammeter would have zero resistance and an ideal voltmeter
infinite resistance?
Question B
Why do the lights on a car become dimmer when the starter is operated?
Question C
Why does current follow the path of least resistance in a parallel circuit?
Question D
Fish like electric eels have specially designed nerve cells that allow them to discharge
hundreds of volts of electricity. Now, while pure water is usually nonconductive, the
dissolved salts and other stuff in both sea and fresh water allow them to be conductive.
If an electric fish is able to use its electricity to stun enemies or prey, how come the fish
itself is unaffected? Hint: think parallel circuit.
Question E
The velocity of the electrons in the wires is very slow (few mm/s), but when one turns on
the light, one doesn't see any delay. Why?