Electrical Resistance and Resistivity

What is the unit of measurement for resistance?

• Voltage

• Ampere

• Watts

• Ohms

What is Resistance?

• the degree to which a circuit component opposes the passage of an electric current, causing energy dissipation
• How hard the energy is pushed
• The amount of charges that pass by a given point per second
• None of the above

How does resistance affect current?

• less resistance - less current
• more resistance - less current
• more resistance - more current
• resistance does not affect current

the formula to find current when the values of V and R are known is

• I = V²R

• I = V/R

• I = R/V

• I=VR

What size resistor would produce a 3 Amp current flow with a 12 Volt battery

• 1 Ohm
• 3 Ohms
• 4 Ohms
• 12 Ohms

Which copper wire has the lowest resistance?

• 1 metre of 1 mm diameter wire
• 0.5 metre of 1 mm diameter wire
• 0.5 metre of 0.5 mm diameter wire
• 1 metere of 0.5 mm diameter wire

What happens to a resistor when the temperature is increased?

• Increases
• decreases
• stay the same
• vary randomly

The length of a certain conductor of resistance 100 is doubled and its cross-sectional area is halved. Its new resistance is

• 100

• 50

• 200

• 400

Factor which does not affect the resistance

• Type of material
• Length of material
• Mass of the material
• Area of the material

Graph shows that _____________

• Resistance is directly proportional to Area
• Resistance is inversely proportional to Area
• Resistance is a constant while Area changes.
• Area is a constant while resistance changes.