19.2 CHAPTER 19. ELECTRIC CIRCUITS
Activity: Ohmic and non-ohmicconductors
Repeat the experiment as described in the previous section. In this case use a light bulb as
a resistor. Compare your results to the ohmic resistor.Using Ohm’s Law ESBII
We are now ready to see how Ohm’s Law is used to analyse circuits.
Consider the circuit withan ohmic resistor, R. If the resistor has a resistance of 5 Ω and voltage across
the resistor is 5 V, then we can use Ohm’s law tocalculate the current flowing through the resistor.
R
Ohm’s law is:
V = R· I
which can be rearrangedto:
I =V
R
The current flowing through the resistor is:
I =
V
R
=
5 V
5 Ω
= 1 A
Example 1: Ohm’s Law
QUESTION