4.4 - Electric and Magnetic Fields

Understand that an electric field is a region where a charged particle experiences a force.

Use - electric fields to connect the rule to the data and decision in the question.

This matters because - electric fields determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - electric fields to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Electric fields is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand electric field strength E = F/Q and use this relationship.

Use - electric field strength to connect the rule to the data and decision in the question.

This matters because - electric field strength determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - electric field strength to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Electric field strength is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use Coulomb's law F = Q1Q2/(4πε0r²) for the force between two point charges.

Use - coulomb’s law to connect the rule to the data and decision in the question.

This matters because - coulomb’s law determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - coulomb’s law to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Coulomb’s law is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use E = Q/(4πε0r²) for the electric field due to a point charge.

Use - electric field due to a point charge to connect the rule to the data and decision in the question.

This matters because - electric field due to a point charge determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - electric field due to a point charge to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Electric field due to a point charge is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know and understand the relationship between electric field and electric potential.

Use - electric field and electric potential to connect the rule to the data and decision in the question.

This matters because - electric field and electric potential determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - electric field and electric potential to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Electric field and electric potential is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use E = V/d for a uniform electric field between parallel plates.

Use - uniform electric field between plates to connect the rule to the data and decision in the question.

This matters because - uniform electric field between plates determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - uniform electric field between plates to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Uniform electric field between plates is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use V = Q/(4πε0r) for electric potential in a radial field.

Use - electric potential in a radial field to connect the rule to the data and decision in the question.

This matters because - electric potential in a radial field determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - electric potential in a radial field to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Electric potential in a radial field is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Draw and interpret field-line and equipotential diagrams for radial and uniform electric fields.

Use - field lines and equipotentials to connect the rule to the data and decision in the question.

This matters because - field lines and equipotentials determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - field lines and equipotentials to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Field lines and equipotentials is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand capacitance C = Q/V and use this relationship.

Use - capacitance to connect the rule to the data and decision in the question.

This matters because - capacitance determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - capacitance to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Capacitance is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use W = ½QV for capacitor energy, derive it from the area under a potential-difference–charge graph, and derive and use W = ½CV² and W = Q²/(2C).

Use - energy stored by a capacitor to connect the rule to the data and decision in the question.

This matters because - energy stored by a capacitor determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - energy stored by a capacitor to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Energy stored by a capacitor is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to draw and interpret charge and discharge curves for resistor capacitor circuits and understand the significance of the time constant RC.

Use - capacitor charge and discharge curves to connect the rule to the data and decision in the question.

This matters because - capacitor charge and discharge curves determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - capacitor charge and discharge curves to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Capacitor charge and discharge curves is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

CORE PRACTICAL 11: Use an oscilloscope or data logger to display and analyse the potential difference (p.d.) across a capacitor as it charges and discharges through a resistor.

Use - core practical 11 - capacitor charging and discharging to connect the rule to the data and decision in the question.

This matters because - core practical 11 - capacitor charging and discharging determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - core practical 11 - capacitor charging and discharging to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Core Practical 11 - capacitor charging and discharging is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use Q = Q0e^(−t/RC), I = I0e^(−t/RC), and V = V0e^(−t/RC) for capacitor discharge, and derive and use ln Q = ln Q0 − t/RC, ln I = ln I0 − t/RC, and ln V = ln V0 − t/RC.

Use - capacitor discharge equations to connect the rule to the data and decision in the question.

This matters because - capacitor discharge equations determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - capacitor discharge equations to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

Understand and use the terms magnetic flux density B, flux φ and flux linkage Nφ.

Use - magnetic flux density, flux and flux linkage to connect the rule to the data and decision in the question.

This matters because - magnetic flux density, flux and flux linkage determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - magnetic flux density, flux and flux linkage to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Magnetic flux density, flux and flux linkage is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to use the equation F = Bqv sinθ and apply Fleming’s left-hand rule to charged particles moving in a magnetic field.

Use - force on a moving charge in a magnetic field to connect the rule to the data and decision in the question.

This matters because - force on a moving charge in a magnetic field determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - force on a moving charge in a magnetic field to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Force on a moving charge in a magnetic field is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to use the equation F = BIl sinθ and apply Fleming’s left-hand rule to current carrying conductors in a magnetic field.

Use - force on a current-carrying conductor to connect the rule to the data and decision in the question.

This matters because - force on a current-carrying conductor determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - force on a current-carrying conductor to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Force on a current-carrying conductor is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the factors affecting the e.m.f. induced in a coil when there is relative motion between the coil and a permanent magnet.

Use - induced e.m.f. from magnet-coil motion to connect the rule to the data and decision in the question.

This matters because - induced e.m.f. from magnet-coil motion determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - induced e.m.f. from magnet-coil motion to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Induced e.m.f. from magnet-coil motion is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the factors affecting the e.m.f. induced in a coil when there is a change of current in another coil linked with this coil.

Use - induced e.m.f. from linked coils to connect the rule to the data and decision in the question.

This matters because - induced e.m.f. from linked coils determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - induced e.m.f. from linked coils to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Induced e.m.f. from linked coils is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use Faraday's law to determine induced e.m.f. and use the combined Faraday–Lenz equation ε = −d(NΦ)/dt.

Use - faraday’s and lenz’s laws to connect the rule to the data and decision in the question.

This matters because - faraday’s and lenz’s laws determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - faraday’s and lenz’s laws to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Faraday’s and Lenz’s laws is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.