Concept Items
19.1 Ohm's law

The electrons flow from the negative terminal of the battery to the positive terminal of the battery.

The electrons flow from the positive terminal of the battery to the negative terminal of the battery.

Current is directly proportional to the resistance.

Current is inversely proportional to the resistance.

Current is proportional to the square of the resistance.

Current is inversely proportional to the square of the resistance.

Resistance is the property of materials to resist the passage of voltage.

Resistance is the property of materials to resist the passage of electric current.

Resistance is the property of materials to increase the passage of voltage.

Resistance is the property of materials to increase the passage of electric current.

V = I^2R

V = \frac{R}{I}

V = \frac{I}{R}

V = IR
19.2 Series Circuits
In which circuit are all the resistors connected in series?
What is the voltage and current through the capacitor in the circuit below a long time after the switch is closed?
 0 V, 0 A
 0 V, 10 A
 10 V, 0 A
 10 V, 10 A
19.3 Parallel Circuits

No, because for a parallel combination of resistors, the resistance through the remaining circuit increases.

Yes, because for a parallel combination of resistors, the resistance through the remaining circuit increases.

Adding resistors in parallel gives the current a shorter path through which it can flow, hence decreasing the overall resistance.

Adding resistors in parallel gives the current another path through which it can flow, hence decreasing the overall resistance.

Adding resistors in parallel reduce the number of paths through which the current can flow, hence decreasing the overall resistance.

Adding resistors in parallel gives the current a longer path through which it can flow, hence decreasing the overall resistance.
19.4 Electric Power
To draw the most power from a battery, should you connect a small or a large resistance across its terminals? Explain.
 Small resistance, because smaller resistance will lead to the largest power
 Large resistance, because smaller resistance will lead to the largest power
If you double the current through a resistor, by what factor does the power dissipated by the resistor change?
 Power increases by a factor of two.
 Power increases by a factor of four.
 Power increases by a factor of eight.
 Power increases by a factor of 16.