Electric Current - AP Physics C: Electricity and Magnetism
Card 1 of 30
What is the drift velocity of electrons?
What is the drift velocity of electrons?
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Average velocity of electrons due to an electric field. Slow net velocity of electrons in conductor.
Average velocity of electrons due to an electric field. Slow net velocity of electrons in conductor.
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What is the unit of electrical power?
What is the unit of electrical power?
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Watt (W). Standard unit for electrical power consumption.
Watt (W). Standard unit for electrical power consumption.
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If $I = 2 , A$ and $R = 3 , \Omega$, find the power $P$ using $P = I^2R$.
If $I = 2 , A$ and $R = 3 , \Omega$, find the power $P$ using $P = I^2R$.
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$P = 12 , W$. Apply $P = I^2R = 2^2 \times 3 = 12$ W.
$P = 12 , W$. Apply $P = I^2R = 2^2 \times 3 = 12$ W.
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What does $L$ represent in $R = \frac{\rho L}{A}$?
What does $L$ represent in $R = \frac{\rho L}{A}$?
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Length of the conductor. Physical length of the conducting material.
Length of the conductor. Physical length of the conducting material.
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What does $A$ represent in $R = \frac{\rho L}{A}$?
What does $A$ represent in $R = \frac{\rho L}{A}$?
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Cross-sectional area of the conductor. Cross-sectional area perpendicular to current flow.
Cross-sectional area of the conductor. Cross-sectional area perpendicular to current flow.
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If $\rho = 1 \Omega \cdot m$, $L = 2 , m$, $A = 1 , m^2$, find $R$.
If $\rho = 1 \Omega \cdot m$, $L = 2 , m$, $A = 1 , m^2$, find $R$.
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$R = 2 , \Omega$. Apply $R = \frac{\rho L}{A} = \frac{1 \times 2}{1} = 2$ Ω.
$R = 2 , \Omega$. Apply $R = \frac{\rho L}{A} = \frac{1 \times 2}{1} = 2$ Ω.
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What is the effect of increasing cross-sectional area on resistance?
What is the effect of increasing cross-sectional area on resistance?
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Resistance decreases. Larger area provides more paths for current.
Resistance decreases. Larger area provides more paths for current.
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State the relationship between current and drift velocity.
State the relationship between current and drift velocity.
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$I = nAve$. Current depends on carrier density, area, and velocity.
$I = nAve$. Current depends on carrier density, area, and velocity.
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What does $Q$ represent in the formula $I = \frac{Q}{t}$?
What does $Q$ represent in the formula $I = \frac{Q}{t}$?
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Charge in Coulombs. Total charge flowing through the circuit.
Charge in Coulombs. Total charge flowing through the circuit.
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What happens to current if resistance increases, assuming constant voltage?
What happens to current if resistance increases, assuming constant voltage?
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Current decreases. Ohm's Law: current inversely proportional to resistance.
Current decreases. Ohm's Law: current inversely proportional to resistance.
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Identify the instrument used to measure electric current.
Identify the instrument used to measure electric current.
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Ammeter. Device connected in series to measure current.
Ammeter. Device connected in series to measure current.
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If $V = 6 , V$ and $R = 2 , \Omega$, find the power $P$ using $P = \frac{V^2}{R}$.
If $V = 6 , V$ and $R = 2 , \Omega$, find the power $P$ using $P = \frac{V^2}{R}$.
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$P = 18 , W$. Apply $P = \frac{V^2}{R} = \frac{36}{2} = 18$ W.
$P = 18 , W$. Apply $P = \frac{V^2}{R} = \frac{36}{2} = 18$ W.
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State the formula for resistance using resistivity.
State the formula for resistance using resistivity.
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$R = \frac{\rho L}{A}$. Resistance depends on material and geometry.
$R = \frac{\rho L}{A}$. Resistance depends on material and geometry.
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Describe the flow of current in a conductor.
Describe the flow of current in a conductor.
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Flow of electrons. Electrons move through conductor creating current.
Flow of electrons. Electrons move through conductor creating current.
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What does $L$ represent in $R = \frac{\rho L}{A}$?
What does $L$ represent in $R = \frac{\rho L}{A}$?
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Length of the conductor. Physical length of the conducting material.
Length of the conductor. Physical length of the conducting material.
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Define conventional current direction.
Define conventional current direction.
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From positive to negative terminal. Convention: current flows from high to low potential.
From positive to negative terminal. Convention: current flows from high to low potential.
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What does $Q$ represent in the formula $I = \frac{Q}{t}$?
What does $Q$ represent in the formula $I = \frac{Q}{t}$?
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Charge in Coulombs. Total charge flowing through the circuit.
Charge in Coulombs. Total charge flowing through the circuit.
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Identify the formula for power in terms of current and voltage.
Identify the formula for power in terms of current and voltage.
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$P = IV$. Power equals voltage times current.
$P = IV$. Power equals voltage times current.
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If $Q = 10 , C$ and $t = 5 , s$, find the current $I$.
If $Q = 10 , C$ and $t = 5 , s$, find the current $I$.
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$I = 2 , A$. Apply $I = \frac{Q}{t} = \frac{10}{5} = 2$ A.
$I = 2 , A$. Apply $I = \frac{Q}{t} = \frac{10}{5} = 2$ A.
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What is the unit of electric current?
What is the unit of electric current?
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Ampere (A). Standard SI unit for electric current flow.
Ampere (A). Standard SI unit for electric current flow.
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State the formula for electric current.
State the formula for electric current.
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$I = \frac{Q}{t}$. Current equals charge divided by time.
$I = \frac{Q}{t}$. Current equals charge divided by time.
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If $V = 6 , V$ and $R = 2 , \Omega$, find the power $P$ using $P = \frac{V^2}{R}$.
If $V = 6 , V$ and $R = 2 , \Omega$, find the power $P$ using $P = \frac{V^2}{R}$.
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$P = 18 , W$. Apply $P = \frac{V^2}{R} = \frac{36}{2} = 18$ W.
$P = 18 , W$. Apply $P = \frac{V^2}{R} = \frac{36}{2} = 18$ W.
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What is the drift velocity of electrons?
What is the drift velocity of electrons?
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Average velocity of electrons due to an electric field. Slow net velocity of electrons in conductor.
Average velocity of electrons due to an electric field. Slow net velocity of electrons in conductor.
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What is the effect of increasing cross-sectional area on resistance?
What is the effect of increasing cross-sectional area on resistance?
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Resistance decreases. Larger area provides more paths for current.
Resistance decreases. Larger area provides more paths for current.
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What is the unit of electrical power?
What is the unit of electrical power?
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Watt (W). Standard unit for electrical power consumption.
Watt (W). Standard unit for electrical power consumption.
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What does $t$ represent in the formula $I = \frac{Q}{t}$?
What does $t$ represent in the formula $I = \frac{Q}{t}$?
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Time in seconds. Duration over which charge flows.
Time in seconds. Duration over which charge flows.
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If $V = 12 , V$ and $R = 3 , \Omega$, find the current $I$.
If $V = 12 , V$ and $R = 3 , \Omega$, find the current $I$.
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$I = 4 , A$. Apply $I = \frac{V}{R} = \frac{12}{3} = 4$ A.
$I = 4 , A$. Apply $I = \frac{V}{R} = \frac{12}{3} = 4$ A.
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What is the relationship between current and voltage in Ohm's Law?
What is the relationship between current and voltage in Ohm's Law?
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$V = IR$. Ohm's Law: voltage equals current times resistance.
$V = IR$. Ohm's Law: voltage equals current times resistance.
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Define resistivity.
Define resistivity.
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Resistance per unit length and cross-sectional area. Material property affecting electrical resistance.
Resistance per unit length and cross-sectional area. Material property affecting electrical resistance.
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What does $P = I^2R$ represent?
What does $P = I^2R$ represent?
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Power formula in terms of current and resistance. Power equals current squared times resistance.
Power formula in terms of current and resistance. Power equals current squared times resistance.
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