AP Physics 2 Flashcards: Electromagnetic Induction And Faradays Law

What this deck covers

This deck focuses on Electromagnetic Induction And Faradays Law, 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: Define the term 'induced current'.

Answer: Current generated in a conductor due to a changing magnetic field. Results from Faraday's Law when flux changes through a conductor.

Flashcard 2: Calculate magnetic flux for $B = 2 \text{T}$ and $A = 3 \text{m}^2$.

Answer: $\text{Φ}_B = 6 \text{Wb}$. Use $\Phi_B = BA$: $2 \times 3 = 6 \text{Wb}$.

Flashcard 3: What is meant by 'induced emf'?

Answer: A voltage generated by changing magnetic fields. The electrical potential difference created by changing magnetic flux.

Flashcard 4: What is the symbol for magnetic flux?

Answer: $\Phi_B$. Greek letter phi with subscript B for magnetic field.

Flashcard 5: How does the number of turns in a coil affect emf?

Answer: More turns increase the induced emf. Each turn contributes to the total induced emf.

Flashcard 6: Explain the role of a solenoid in electromagnetic induction.

Answer: A solenoid can enhance the magnetic field and hence induce emf. Multiple turns multiply the induced emf effect.

Flashcard 7: What is Lenz's Law?

Answer: The direction of the induced current opposes the change in magnetic flux. Explains the negative sign in Faraday's Law equation.

Flashcard 8: Which factor affects the magnitude of induced emf?

Answer: Rate of change of magnetic flux. Faster flux changes produce larger induced emf magnitudes.

Flashcard 9: State the formula for Faraday's Law.

Answer: $\text{emf} = -\frac{d\Phi_B}{dt}$. The negative sign represents Lenz's Law - opposition to flux change.

Flashcard 10: Which factor affects the magnitude of induced emf?

Answer: Rate of change of magnetic flux. Faster flux changes produce larger induced emf magnitudes.

Flashcard 11: What is the role of a galvanometer in induction experiments?

Answer: To measure the induced current. Detects and measures small currents in induction experiments.

Flashcard 12: Find induced emf for $\text{Φ}_B$ change from 10 Wb to 5 Wb in 2 s.

Answer: $\text{emf} = -2.5 \text{V}$. Use $\text{emf} = -\frac{\Delta\Phi_B}{\Delta t} = -\frac{5-10}{2} = -2.5 \text{V}$.

Flashcard 13: What is the role of a galvanometer in induction experiments?

Answer: To measure the induced current. Detects and measures small currents in induction experiments.

Flashcard 14: What does the term 'emf' stand for?

Answer: Electromotive force. The potential difference induced by changing magnetic flux.

Flashcard 15: How does a closed loop influence induced emf?

Answer: A closed loop allows an induced current to flow. Provides a complete path for induced current circulation.

Flashcard 16: Define the term 'flux linkage'.

Answer: Product of the magnetic flux and the number of turns in a coil. Total magnetic flux linking all turns of a coil.

Flashcard 17: What happens if magnetic field strength is constant?

Answer: No change in magnetic flux and no induced emf. Constant field means $\frac{d\Phi_B}{dt} = 0$, so no emf.

Flashcard 18: What is the effect of increasing magnetic field strength on flux?

Answer: Magnetic flux increases. More field lines pass through the same area.

Flashcard 19: What does Faraday's Law of Induction state?

Answer: The induced emf is equal to the negative rate of change of magnetic flux. This is the fundamental principle governing electromagnetic induction.

Flashcard 20: Explain the role of a solenoid in electromagnetic induction.

Answer: A solenoid can enhance the magnetic field and hence induce emf. Multiple turns multiply the induced emf effect.

Flashcard 21: Calculate magnetic flux for $B = 2 \text{T}$ and $A = 3 \text{m}^2$.

Answer: $\text{Φ}_B = 6 \text{Wb}$. Use $\Phi_B = BA$: $2 \times 3 = 6 \text{Wb}$.

Flashcard 22: Define magnetic flux.

Answer: Magnetic flux is the product of the magnetic field and the area through which it passes. Quantifies how much magnetic field passes through a surface.

Flashcard 23: What is meant by 'induced emf'?

Answer: A voltage generated by changing magnetic fields. The electrical potential difference created by changing magnetic flux.

Flashcard 24: Find induced emf for $\text{Φ}_B$ change from 10 Wb to 5 Wb in 2 s.

Answer: $\text{emf} = -2.5 \text{V}$. Use $\text{emf} = -\frac{\Delta\Phi_B}{\Delta t} = -\frac{5-10}{2} = -2.5 \text{V}$.

Flashcard 25: What does the negative sign in Faraday's Law signify?

Answer: Opposition to change in magnetic flux (Lenz's Law). Represents Lenz's Law - induced effects oppose the change.

Flashcard 26: Identify the unit of electromotive force (emf).

Answer: Volt (V). Same unit as voltage since emf represents induced potential difference.

Flashcard 27: What happens to emf if the magnetic field is uniform?

Answer: No change in flux, no induced emf. Uniform field means no spatial flux variation.

Flashcard 28: What does the negative sign in Faraday's Law signify?

Answer: Opposition to change in magnetic flux (Lenz's Law). Represents Lenz's Law - induced effects oppose the change.

Flashcard 29: What factor does not affect the magnitude of induced emf?

Answer: Resistance of the coil. Resistance affects current, not the induced emf magnitude.

Flashcard 30: State the relationship between magnetic flux and area.

Answer: Magnetic flux is directly proportional to the area. Larger area allows more field lines to pass through.

Flashcard 31: What unit is used to measure magnetic flux?

Answer: Weber (Wb). Named after Wilhelm Weber, equivalent to $\text{T}\cdot\text{m}^2$.

Flashcard 32: How does moving a magnet in a coil induce emf?

Answer: It changes the magnetic flux through the coil. Motion changes the magnetic flux through the coil.

Flashcard 33: What happens to emf if the magnetic field is uniform?

Answer: No change in flux, no induced emf. Uniform field means no spatial flux variation.

Flashcard 34: What is the result of a constant magnetic flux through a coil?

Answer: No induced emf. No flux change means $\frac{d\Phi_B}{dt} = 0$, so emf = 0.

Flashcard 35: What is the result of a constant magnetic flux through a coil?

Answer: No induced emf. No flux change means $\frac{d\Phi_B}{dt} = 0$, so emf = 0.

Flashcard 36: Calculate induced emf for $\frac{d\text{Φ}_B}{dt} = -3 \text{Wb/s}$.

Answer: $\text{emf} = 3 \text{V}$. Apply Faraday's Law: $\text{emf} = -(-3) = 3 \text{V}$.

Flashcard 37: What is the impact of increasing coil area on emf?

Answer: Increases magnetic flux and induces greater emf. Larger area captures more magnetic flux for induction.

Flashcard 38: How does Lenz's Law relate to the conservation of energy?

Answer: Induced emf opposes the change to conserve energy. Opposition prevents creation of energy from nothing.

Flashcard 39: Calculate magnetic flux for $B = 1 \text{T}$, $A = 4 \text{m}^2$.

Answer: $\text{Φ}_B = 4 \text{Wb}$. Use $\Phi_B = BA$: $1 \times 4 = 4 \text{Wb}$.

Flashcard 40: How does the number of turns in a coil affect emf?

Answer: More turns increase the induced emf. Each turn contributes to the total induced emf.

Flashcard 41: What is the relationship between emf and coil orientation?

Answer: Emf is maximized when the coil is perpendicular to the magnetic field. Maximum flux change occurs when perpendicular to field lines.

Flashcard 42: Identify one application of electromagnetic induction.

Answer: Electric generators. Converts mechanical energy to electrical energy using induction.

Flashcard 43: What is the impact of increasing coil area on emf?

Answer: Increases magnetic flux and induces greater emf. Larger area captures more magnetic flux for induction.

Flashcard 44: Define the term 'induced current'.

Answer: Current generated in a conductor due to a changing magnetic field. Results from Faraday's Law when flux changes through a conductor.

Flashcard 45: Which physical quantity does a change in magnetic flux induce?

Answer: Electromotive force (emf). A changing flux creates a potential difference across the conductor.

Flashcard 46: State the relationship between magnetic flux and area.

Answer: Magnetic flux is directly proportional to the area. Larger area allows more field lines to pass through.

Flashcard 47: State the formula for Faraday's Law.

Answer: $\text{emf} = -\frac{d\text{Φ}_B}{dt}$. The negative sign represents Lenz's Law - opposition to flux change.

Flashcard 48: What unit is used to measure magnetic flux?

Answer: Weber (Wb). Named after Wilhelm Weber, equivalent to $\text{T}\cdot\text{m}^2$.

Flashcard 49: What factor does not affect the magnitude of induced emf?

Answer: Resistance of the coil. Resistance affects current, not the induced emf magnitude.

Flashcard 50: Find the induced emf if $\frac{d\text{Φ}_B}{dt} = 5 \text{Wb/s}$.

Answer: $\text{emf} = -5 \text{V}$. Apply Faraday's Law: $\text{emf} = -\frac{d\Phi_B}{dt} = -5 \text{V}$.

Flashcard 51: What happens if magnetic field strength is constant?

Answer: No change in magnetic flux and no induced emf. Constant field means $\frac{d\Phi_B}{dt} = 0$, so no emf.

Flashcard 52: Define the term 'flux linkage'.

Answer: Product of the magnetic flux and the number of turns in a coil. Total magnetic flux linking all turns of a coil.

Flashcard 53: What does Faraday's Law of Induction state?

Answer: The induced emf is equal to the negative rate of change of magnetic flux. This is the fundamental principle governing electromagnetic induction.

Flashcard 54: Identify the unit of electromotive force (emf).

Answer: Volt (V). Same unit as voltage since emf represents induced potential difference.

Flashcard 55: Explain mutual induction.

Answer: Inducing emf in one coil due to change in current in another. Current change in one coil induces emf in nearby coil.

Flashcard 56: What is the main principle behind transformers?

Answer: Electromagnetic induction. Uses changing magnetic flux to transfer energy between coils.

Flashcard 57: Define magnetic flux.

Answer: Magnetic flux is the product of the magnetic field and the area through which it passes. Quantifies how much magnetic field passes through a surface.

Flashcard 58: What is the effect of increasing magnetic field strength on flux?

Answer: Magnetic flux increases. More field lines pass through the same area.

Flashcard 59: What is the relationship between emf and coil orientation?

Answer: Emf is maximized when the coil is perpendicular to the magnetic field. Maximum flux change occurs when perpendicular to field lines.

Flashcard 60: How does moving a magnet in a coil induce emf?

Answer: It changes the magnetic flux through the coil. Motion changes the magnetic flux through the coil.

Flashcard 61: Identify the unit for magnetic field strength.

Answer: Tesla (T). Measures magnetic field intensity or flux density.

Flashcard 62: Explain mutual induction.

Answer: Inducing emf in one coil due to change in current in another. Current change in one coil induces emf in nearby coil.

Flashcard 63: Calculate magnetic flux for $B = 1 \text{T}$, $A = 4 \text{m}^2$.

Answer: $\text{Φ}_B = 4 \text{Wb}$. Use $\Phi_B = BA$: $1 \times 4 = 4 \text{Wb}$.

Flashcard 64: State one way to increase induced emf.

Answer: Increase the rate of change of magnetic flux. Faster flux changes produce larger emf by Faraday's Law.

Flashcard 65: Identify one application of electromagnetic induction.

Answer: Electric generators. Converts mechanical energy to electrical energy using induction.

Flashcard 66: What does the term 'emf' stand for?

Answer: Electromotive force. The potential difference induced by changing magnetic flux.

Flashcard 67: State one way to increase induced emf.

Answer: Increase the rate of change of magnetic flux. Faster flux changes produce larger emf by Faraday's Law.

Flashcard 68: Which physical quantity does a change in magnetic flux induce?

Answer: Electromotive force (emf). A changing flux creates a potential difference across the conductor.

Flashcard 69: How does Lenz's Law relate to the conservation of energy?

Answer: Induced emf opposes the change to conserve energy. Opposition prevents creation of energy from nothing.

Flashcard 70: How does a closed loop influence induced emf?

Answer: A closed loop allows an induced current to flow. Provides a complete path for induced current circulation.

Flashcard 71: What is the main principle behind transformers?

Answer: Electromagnetic induction. Uses changing magnetic flux to transfer energy between coils.

Flashcard 72: What is Lenz's Law?

Answer: The direction of the induced current opposes the change in magnetic flux. Explains the negative sign in Faraday's Law equation.

Flashcard 73: Identify the unit for magnetic field strength.

Answer: Tesla (T). Measures magnetic field intensity or flux density.

Flashcard 74: Find the induced emf if $\frac{d\text{Φ}_B}{dt} = 5 \text{Wb/s}$.

Answer: $\text{emf} = -5 \text{V}$. Apply Faraday's Law: $\text{emf} = -\frac{d\Phi_B}{dt} = -5 \text{V}$.

Flashcard 75: Calculate induced emf for $\frac{d\text{Φ}_B}{dt} = -3 \text{Wb/s}$.

Answer: $\text{emf} = 3 \text{V}$. Apply Faraday's Law: $\text{emf} = -(-3) = 3 \text{V}$.