AP Physics 2 Flashcards: Electric Current

What this deck covers

This deck focuses on Electric Current, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 2.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Calculate the potential difference if $I = 1.5 \text{ A}$ and $R = 6 \text{ Ω}$.

Answer: $V = 9 \text{ V}$. Apply $V = IR = 1.5 \times 6 = 9$ V.

Flashcard 2: What is the unit of electrical power?

Answer: Watt (W). Rate of energy transfer or consumption.

Flashcard 3: Convert 1 milliampere to amperes.

Answer: $1 \text{ mA} = 0.001 \text{ A}$. Milli prefix means one thousandth.

Flashcard 4: Calculate the energy used if $P = 100 \text{ W}$ and $t = 2 \text{ hours}$.

Answer: $E = 200 \text{ Wh}$. Apply $E = Pt = 100 \times 2 = 200$ Wh.

Flashcard 5: What is the formula for total resistance in series?

Answer: $R_{total} = R_1 + R_2 + \\dots$. Individual resistances add in series circuits.

Flashcard 6: State the formula for calculating resistance using resistivity.

Answer: $R = \frac{\rho L}{A}$. Resistance depends on material, length, and cross-sectional area.

Flashcard 7: What is the definition of resistivity?

Answer: Resistance per unit length and area. Material property affecting electrical resistance.

Flashcard 8: What is the unit of resistance?

Answer: Ohm ($\text{Ω}$). Named after Georg Ohm, symbol omega.

Flashcard 9: What is the effect of adding resistors in parallel on total resistance?

Answer: Total resistance decreases. Parallel paths reduce overall resistance.

Flashcard 10: What is the effect of temperature on resistance in conductors?

Answer: Resistance increases. Higher temperature increases atomic vibrations.

Flashcard 11: What is the formula for electrical power in terms of current and voltage?

Answer: $P = IV$. Power equals current times voltage.

Flashcard 12: Calculate the potential difference if $I = 1.5 \text{ A}$ and $R = 6 \text{ Ω}$.

Answer: $V = 9 \text{ V}$. Apply $V = IR = 1.5 \times 6 = 9$ V.

Flashcard 13: What does an ohmmeter measure?

Answer: Resistance. Instrument for measuring electrical resistance.

Flashcard 14: How is current measured?

Answer: Using an ammeter. Ammeter connected in series with circuit.

Flashcard 15: Calculate the energy used if $P = 100 \text{ W}$ and $t = 2 \text{ hours}$.

Answer: $E = 200 \text{ Wh}$. Apply $E = Pt = 100 \times 2 = 200$ Wh.

Flashcard 16: What is the power formula using voltage and resistance?

Answer: $P = \frac{V^2}{R}$. Alternative power formula using voltage and resistance.

Flashcard 17: What does an ohmmeter measure?

Answer: Resistance. Instrument for measuring electrical resistance.

Flashcard 18: What is the formula for voltage in terms of work and charge?

Answer: $V = \frac{W}{q}$. Voltage is work per unit charge.

Flashcard 19: Calculate the current if $V = 12 \text{ V}$ and $R = 4 \text{ Ω}$. Use Ohm's Law.

Answer: $I = 3 \text{ A}$. Apply $I = \frac{V}{R} = \frac{12}{4} = 3$ A.

Flashcard 20: Calculate resistance if $V = 10 \text{ V}$ and $I = 2 \text{ A}$. Use Ohm's Law.

Answer: $R = 5 \text{ Ω}$. Apply $R = \frac{V}{I} = \frac{10}{2} = 5$ Ω.

Flashcard 21: What is the effect of increasing voltage on current, assuming constant resistance?

Answer: Current increases. Direct proportional relationship from Ohm's Law.

Flashcard 22: What is the formula for total resistance in parallel?

Answer: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \\dots$. Reciprocals of resistances add in parallel circuits.

Flashcard 23: State Ohm's Law formula.

Answer: $V = IR$. Voltage equals current times resistance.

Flashcard 24: What is the formula for voltage in terms of work and charge?

Answer: $V = \frac{W}{q}$. Voltage is work per unit charge.

Flashcard 25: State Ohm's Law formula.

Answer: $V = IR$. Voltage equals current times resistance.

Flashcard 26: What is the formula for electric current in terms of charge and time?

Answer: $I = \frac{q}{t}$. Current is charge divided by time.

Flashcard 27: What is the effect of increasing resistance on current?

Answer: Current decreases. Inverse relationship from Ohm's Law.

Flashcard 28: What is the unit of resistivity?

Answer: $\text{Ωm}$ (Ohm meter). Resistance times meters per square meter.

Flashcard 29: What is the effect of adding resistors in series on total resistance?

Answer: Total resistance increases. Resistors in series add directly.

Flashcard 30: What is Kirchhoff's Junction Rule?

Answer: Sum of currents entering = sum leaving. Conservation of charge at circuit junctions.

Flashcard 31: Identify the direction of conventional current flow.

Answer: From positive to negative terminal. Conventional current flows opposite to electron flow.

Flashcard 32: Describe the motion of electrons in a conductor.

Answer: Drift towards positive terminal. Electrons move opposite to conventional current direction.

Flashcard 33: What is the formula for total resistance in parallel?

Answer: $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \\dots$. Reciprocals of resistances add in parallel circuits.

Flashcard 34: What is the effect of increasing voltage on current, assuming constant resistance?

Answer: Current increases. Direct proportional relationship from Ohm's Law.

Flashcard 35: What is the effect of adding resistors in parallel on total resistance?

Answer: Total resistance decreases. Parallel paths reduce overall resistance.

Flashcard 36: Express 5 kilowatts in watts.

Answer: $5 \text{ kW} = 5000 \text{ W}$. Kilo prefix means one thousand.

Flashcard 37: What is the unit for electric charge?

Answer: Coulomb (C). Amount of electric charge, named after Coulomb.

Flashcard 38: Define electric current.

Answer: Flow of electric charge. Rate of charge flow through a conductor.

Flashcard 39: Calculate the power if $I = 2 \text{ A}$ and $R = 3 \text{ Ω}$. Use $P = I^2R$.

Answer: $P = 12 \text{ W}$. Apply $P = I^2R = 2^2 \times 3 = 12$ W.

Flashcard 40: What is the effect of increasing resistance on current?

Answer: Current decreases. Inverse relationship from Ohm's Law.

Flashcard 41: Calculate the current if $V = 12 \text{ V}$ and $R = 4 \text{ Ω}$. Use Ohm's Law.

Answer: $I = 3 \text{ A}$. Apply $I = \frac{V}{R} = \frac{12}{4} = 3$ A.

Flashcard 42: Identify the direction of conventional current flow.

Answer: From positive to negative terminal. Conventional current flows opposite to electron flow.

Flashcard 43: What is the relationship between power, current, and resistance?

Answer: $P = I^2R$. Power dissipated as heat in resistive circuits.

Flashcard 44: What is the formula for total resistance in series?

Answer: $R_{total} = R_1 + R_2 + \\dots$. Individual resistances add in series circuits.

Flashcard 45: Calculate the total resistance for $R_1 = 5 \text{ Ω}$ and $R_2 = 10 \text{ Ω}$ in parallel.

Answer: $R_{total} = 3.33 \text{ Ω}$. Apply $\frac{1}{R_{total}} = \frac{1}{5} + \frac{1}{10} = \frac{3}{10}$, so $R_{total} = 3.33$ Ω.

Flashcard 46: What is the power formula using voltage and resistance?

Answer: $P = \frac{V^2}{R}$. Alternative power formula using voltage and resistance.

Flashcard 47: Calculate the total resistance for $R_1 = 5 \text{ Ω}$ and $R_2 = 10 \text{ Ω}$ in parallel.

Answer: $R_{total} = 3.33 \text{ Ω}$. Apply $\frac{1}{R_{total}} = \frac{1}{5} + \frac{1}{10} = \frac{3}{10}$, so $R_{total} = 3.33$ Ω.

Flashcard 48: What is the unit of electrical power?

Answer: Watt (W). Rate of energy transfer or consumption.

Flashcard 49: How is current measured?

Answer: Using an ammeter. Ammeter connected in series with circuit.

Flashcard 50: What is the SI unit for electric current?

Answer: Ampere (A). Standard unit defined as one coulomb per second.

Flashcard 51: Convert 1 milliampere to amperes.

Answer: $1 \text{ mA} = 0.001 \text{ A}$. Milli prefix means one thousandth.

Flashcard 52: State the formula for electrical energy in terms of power and time.

Answer: $E = Pt$. Energy equals power multiplied by time.