## PHYS208 Fundamentals of Physics II

### Hint for Ch. 28, 14E

The tank and indcator resistances are in series.

### Hint for Ch. 28, 33E

There are 8 possible combinations!
Ignoring the trivial case where all switches are open (no current),
there are three settings with one switch closed,
three different circuits with two switches closed,
and yet a different circuit when all three switches are closed.
Even though this exercise involves a lot of drawing and algebraic manipulation, if you are able to complete all seven circuits satisfactorally,
then you may feel confident that you understand how to deal with
combinations of series and parallel resistors.

### Hint for Ch. 28, 38E

Please see my detailed series/paralled circuit example.

### Hint for Ch. 28, 55P

R_{2} and R_{3} are in parallel, assuming a "perfect" ammeter of 0 ohm
resistance.
This parallel combination is then in series with R_{1} so that the circuit reduces
to a simple equivalent circuit from which the current through the emf
(and R_{1}) may be calculated.
Finally, establish the voltage across the parallel combination and from that deduce the
current through the ammeter (and R_{3}).

"http://www.physics.udel.edu/~watson/phys208/exercises/hints/0220.html"

Last updated Feb. 18, 1998.

Copyright George Watson, Univ. of Delaware, 1997.