Circuit Resistance

Resistivity of a wire depends on:

• length
• material
• cross sectional area
• none of the above

™A circuit has 120 volts, and a 45 ohm resistor. How much current is there?

• 5400 A
• 2.7 A
• 0.375 A
• 165 A

What is Voltage?

• The flow of electrons
• Electric potential difference
• A battery
• The ability to reduce the flow of electrons

What is Current?

• The flow of electrons
• Electric potential difference
• A battery
• The ability to reduce the flow of electrons

What is Resistance?

• The flow of electrons
• Electric potential difference
• A battery
• The ability to reduce the flow of electrons

™What are the units for Voltage?

• Watts
• Volts
• Ohms
• Amps

™What are the units for Current?

• Watts
• Volts
• Ohms
• Amps

™What are the units for Power?

• Watts
• Volts
• Ohms
• Amps

™What are the units for Resistance?

• Watts
• Volts
• Ohms
• Amps

™What is the resistance of one million meters of copper wire (copper resistivity is 1.68x10-8 ohm m), with a diameter of 500 cm.

• 8.58 10-4 ohms
• 2.1310-4 ohms
• 0.0168 volts
• 2.13 10-4 amps