9.3 Resistance [Must do] 1

Electrical resistance is . . .

• the amount of energy transferred per unit of charge.

• the rate of flow of electric charge.

• a material's opposition to the flow of charge.

The scientific symbol for resistance is _____

• Ω

• R

• I

• V

Resistance is measured in . . .

• amps.

• ohms.

• joules.

• volts.

Different materials have different resistances. It's easy for a current to flow through an electrical conductor, such as copper, because it has . . .

• a high resistance.

• a low resistance.

Different materials have different resistances. It's difficult for a current to flow through an electrical insulator, such as plastic, because it has . . .

• a high resistance.

• a low resistance.

The resistance of a wire is affected by its length. Wire B has a ...................... resistance than wire A because it's longer.

• higher
• lower

Wire D has a ................... resistance than wire C because it's thicker.

• higher
• lower

• equal

The resistance of a wire is affected by its temperature. Wire F has a (a)   resistance than wire E because it is hotter.

• higher
• lower

Less current flows through a circuit with two lamps than a circuit with one lamp because increasing the number of components ....................... the resistance.

• increases
• doesn't affect

• decreases

You can find the resistance of a component experimentally by measuring the ________ across a component and the current through the component, then using the equation in the image to calculate resistance.

• voltage

• temperature

• pressure

• frequency