$$Chapter Objectives

1. Calculate the resistance of a system of resistors that are connected in parallel and series.
2. Define and describe Kirchhoff's rules for electrical d.c. circuits.
3. Calculate the time constant for an RC circuit.

Conceptual Questions

1. Is the direction of current through a battery always from negative to positive on the terminals?
2. Would a fuse work successfully if it were placed in parallel with the device it was supposed to protect?
3. When electricians (at least live ones) work with potentially live wires, they often use the backs of their hands or fingers to move the wires. Why do you suppose they do this?
4. If you were unable to get indoors during an electrical storm, how would you protect yourself?

Problems

1. A 4.0 ohm resistor, an 8.0 ohm resistor, and a 12.0 ohm resistor are connected in series with a 24 V battery. What are (a) the equivalent resistance and (b) the current in each resistor?
2. Consider a series RC circuit for which C = 6.0 x 10^-6 F, R = 2.0 x 10⁶ ohms, and E = 20 V. Find (a) the time constant of the circuit and (b) the maximum charge on the capacitor after a switch in the circuit is closed.

Solutions

If you find an error in these, or just have a comment, send an e-mail message to jpratte@astate.edu