Ohm’s law says that when electric current is flowing across a resistor, the current i, measured in amperes, can be calculated from the voltage v, measured in volts, and the resistance R, measured in ohms. The relationship is given by
a. Aresistor in a radio circuit is rated at 4000 ohms.
i. Find a formula for the current as a function of the voltage.
ii. Plot the graph of i versus v. Include values of the voltage up to 12 volts.
iii. What happens to the current when voltage increases?
b. The lights on your car operate on a 12-volt battery.
i. Find a formula for the current in your car lights as a function of the resistance.
ii. Plot the graph of i versus R. We suggest a horizontal span here of 1 to 25.
iii. What happens to the current when resistance increases?