Electric Current

Electric Current

Revision

Multiple Choice

What does power mean?

• Joules transferred per second

• Electron flow per second

• Speed of electrons

• Electron energy

Multiple Choice

If the voltage stays the same and Resistance is increased, the Current will

• Increase

• Decrease

• Stay the same

• Not enough info

Multiple Choice

If the voltage stays the same, but the resistance goes up the current will....

• increase (speed up)

• decrease (slow down)

• stay the same

Multiple Choice

Resistance is...

• What "slows down" electrons
• What "speeds up" electrons
• Moving electrons
• What "pushes" electrons

Multiple Choice

Voltage is simply defined as...

• what 'pushes' electrons
• what 'stops' electrons
• moving electrons

Multiple Choice

If electrical power costs $0.12/kwh, and I use 9 x 10⁸ Joules of electrical energy, what will I be charged?

• $10

• $20

• $30

• $40

Multiple Choice

Which of the following equations is an equation for power, involving current and resistance?

• P= I/V

• P = IR

• P = IVR²

• P = I²R

Multiple Choice

superconductor

• material with high resistance

• material with low resistance

• material with half resistance

• material with zero resistance

Multiple Choice

How much energy does a 100-W light bulb use in 8.0 hours?

• 0.0080 kWh

• 0.80 kWh

• 13 kWh

• 800 kWh

Multiple Choice

What is the resistance of a 0.100-kW light bulb designed to be used in a 120-V circuit dc?

• 12.0 Ω

• 144 Ω

• 1.2 Ω

• 0.83 Ω

Multiple Choice

When 5.00 A is flowing through an 10.0-Ω device, how much power is being dissipated in the device?

• 50.0 W

• 250 W

• 500 W

• 2.50 kW

Multiple Choice

A 100-W light bulb is operated by a 110-V dc source. What is the resistance of this bulb?

• 100 Ω

• 8.0 × 10^-3 Ω

• 120 Ω

• 240 Ω

Multiple Choice

A 200-W light bulb is connected across a 100-V dc power supply. What current will flow through this bulb?

• 0.90 A

• 0.36 A

• 0.60 A

• 2.0 A

Multiple Choice

A 4000-Ω resistor is connected across a 220-V power source. What current will flow through the resistor?

• 0.055 A

• 1.8 A

• 5.5 A

• 18 A

Multiple Choice

What potential difference is required across an 8.0-Ω resistor to cause 2.0 A to flow through it?

• 4.0 V

• 16 V

• 8.0 V

• 32 V

Multiple Choice

If the voltage across a circuit of constant resistance is doubled, the power dissipated by that circuit will

• be four times as large.

• be two times as large.

• decrease to one-half the original power.

• decrease to one-fourth the original power.

Multiple Choice

If the resistance in a constant voltage circuit is doubled, the power dissipated by that circuit will

• increase by a factor of two.

• increase by a factor of four.

• decrease to one-half its original value.

• decrease to one-fourth its original value.

Multiple Choice

A kilowatt-hour is equivalent to

• 1000 W.

• 3600 J.

• 3,600,000 J/s.

• 3,600,000 J.

Multiple Choice

Which one of the following quantities is equivalent to 1 W?

• 1 V/A

• 1 Ω • m

• 1 V • A

• 1 V/Ω