| Objective: |
| To illustrate Ohm's law - defining the direction
of voltage and current. |
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The direction of the voltage across the resistor
can be defined in terms of voltmeter measurements. |
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In the simple circuit shown the current is the same
everywhere. The voltage across the resistor is defined. |
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When we draw circuit diagrams we usually assume
that the wiring has zero resistance. |
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This means that the voltage drop across the resistor
is the same as the battery voltage. |
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The relationship between the voltage across and
current through a resistor is termed Ohm's Law. Note the direction
of the current flow and voltage drop. |