All Flashcards
What is the definition of Current Density (J)?
Current per unit area (A/m²). It's a vector related to the electric field (E) by J = E/ρ, where ρ is resistivity.
What is the definition of Resistivity (ρ)?
A material's opposition to the flow of electric current, measured in Ω⋅m.
What is the definition of Resistance (R)?
The overall opposition to current flow in a specific object, measured in Ohms (Ω).
What is the definition of Electromotive Force (EMF or ε)?
The total energy a battery can provide per unit charge, measured in Volts. It's the voltage before any current flows.
What is the definition of Terminal Voltage (Vₜ)?
The actual voltage available in a circuit when current is flowing, which is less than the EMF due to internal resistance.
What is the definition of Internal Resistance (r)?
The resistance within a battery that causes the terminal voltage to be less than the EMF when current flows.
What are the differences between Resistivity (ρ) and Resistance (R)?
Resistivity: Material property (Ω⋅m), independent of dimensions | Resistance: Object property (Ω), depends on material, length, and area.
What are the differences between Ohmic and Non-Ohmic devices?
Ohmic: Follows Ohm's Law (V=IR), linear V-I graph | Non-Ohmic: Does not follow Ohm's Law, non-linear V-I graph.
What are the differences between EMF and Terminal Voltage?
EMF: Total voltage provided by a battery before current flows | Terminal Voltage: Actual voltage available in a circuit when current is flowing, accounting for internal resistance.
Compare and contrast resistors in series and parallel.
Series: Current is the same through all resistors, total resistance increases. | Parallel: Voltage is the same across all resistors, total resistance decreases.
In the circuit diagram of EMF, label the EMF, internal resistance, and terminal voltage.
1: EMF (ε), 2: Internal Resistance (r), 3: Terminal Voltage (V_T)
Label the components in a simple series circuit diagram with a battery and two resistors.
1: Battery (Voltage Source), 2: Resistor R1, 3: Resistor R2
Label the components in a simple parallel circuit diagram with a battery and two resistors.
1: Battery (Voltage Source), 2: Resistor R1, 3: Resistor R2