Electricity Review

Which of the following does NOT affect a material's resistance?

• the type of material

• temperature

• Ohm's law

• length of the wire

Which of the following wires would have the MOST resistance?

• an aluminium wire 20 cm in diameter at 40 degrees Celsius

• an aluminium wire 40 cm in diameter at 40 degrees Celsius

• an aluminium wire 40 cm in diameter at 60 degrees Celsius

• an aluminium wire 20 cm in diameter at 60 degrees Celsius

The amount of charge that moves through the filament of a light bulb in 3.0 s is 4.5 C. What is the current in the light bulb?

• 13.5 A

• 1.5 A

• 0.835 A

• 5.34 A

Which process will half the power dissipated by a resistor?

• doubling the current while doubling the resistance

• doubling the current while making the potential difference half as big

• doubling the current and doubling the potential difference

• doubling the current and making the resistance half as big

As the temperature in a wire goes up, ___.

• the resistance and current go up.

• the resistance goes up while the current goes down.

• the resistance and current remain unchanged.

• the resistance goes down while the current goes up.

As the length of a wire in a circuit decreases, ___.

• the resistance decreases while the current increases.

• the resistance increases while the current decreases.

• the current and the resistance increase.

• the current and the resistance decrease.

As the cross-sectional area of a wire increases, ___.

• the resistance and current increase.

• the resistance and the current decrease.

• the resistance and the current remain unchanged.

• the resistance decreases while the current increases.

In a series circuit, the ___ is equal for all resistors.

• resistance

• voltage

• current

• temperature

To find the equivalent resistance of a series circuit, ___.

• R_E = R₁ + R₂ + R₃ ...

• R_E = 1/(1/R₁ + 1/R_{2 + 1/R3} ...)

• R_E = R₁ = R₂ = R₃ ...

• R_E = 1/R₁ + 1/R₂ + 1/R₃ ...

To find the equivalent resistance of a parallel circuit,

• R_E = R₁ + R₂ + R₃ ...

• R_E = 1 / (1/R₁ + 1/R₂ + 1/R₃ ...)

• R_E = R₁ = R₂ = R₃ ...

• R_E = 1/R_{1 +} 1/R₂ + 1/R₃ ...