Skip to main content
Pearson+ LogoPearson+ Logo

Resistors and Ohm's Law quiz Flashcards

Resistors and Ohm's Law quiz
Control buttons has been changed to "navigation" mode.
1/10
  • What is the effect on resistance if the radius of a vessel is halved?
    The resistance of a conductor is inversely proportional to its cross-sectional area (A), which is related to the radius (r) by the formula A = πr². If the radius is halved, the cross-sectional area becomes one-fourth of its original value. Since resistance (R) is inversely proportional to the area (R = ρL/A), halving the radius results in the resistance increasing by a factor of four.
  • What is Ohm's Law and its equation?
    Ohm's Law is a fundamental equation in physics that relates voltage, current, and resistance, expressed as V = IR.
  • How does resistance affect the flow of electric current in a conductor?
    Resistance opposes the flow of electric current, resulting in a smaller amount of current passing through the conductor.
  • What is the relationship between resistance, resistivity, length, and cross-sectional area of a conductor?
    Resistance (R) is given by the formula R = ρ(L/A), where ρ is resistivity, L is length, and A is cross-sectional area.
  • How do you calculate current if you know the charge and time?
    Current (I) is calculated by dividing the charge (ΔQ) by the time (Δt), I = ΔQ/Δt.
  • What is the unit of resistance and its symbol?
    The unit of resistance is ohms, represented by the Greek letter omega (Ω).
  • What is resistivity and how is it measured?
    Resistivity is a material-specific property that indicates how strongly a material opposes electric current, measured in ohm-meters (Ω·m).
  • How do you calculate the resistivity of a wire given its resistance, length, and diameter?
    Resistivity (ρ) is calculated using the formula ρ = R(A/L), where A is the cross-sectional area (πr²) and L is the length.
  • Why are wires in circuit problems often assumed to have zero resistance?
    Wires are assumed to have zero resistance to simplify calculations, although they have a very small, non-zero resistance.
  • How do you find the current in a wire if you know the voltage and resistance?
    Current (I) is found using Ohm's Law, I = V/R, where V is voltage and R is resistance.