OCR A-Level Physics A H556
Practical Skills in the Written Papers
The Practical Endorsement
Physical Quantities and Units
Making Measurements and Analysing Data
Nature of Quantities
Motion
Forces in Action
Work, Energy and Power
Materials
Newton’s Laws of Motion and Momentum
Charge and Current
Energy, Power and Resistance
Electrical Circuits
Waves
Quantum Physics
Thermal Physics
Oscillations
Gravitational Fields
Astrophysics and Cosmology
Capacitors
Electric Fields
Electromagnetism
Nuclear and Particle Physics
Electromagnetism
Magnetic flux, flux linkage and Faraday's law
- 3 things to know
- Papers 1, 2 and 3
Overview
Recall questions on the weber, magnetic flux linkage, Faraday's law and Lenz's law, calculating induced e.m.f., and changing the flux linkage through a search coil.
What you need to know
Answer each one before you reveal it.
Define one weber in terms of tesla and square metre.
Define magnetic flux linkage for a coil.
Questions from this subtopic
Each one with the model answer underneath.
- 1
Define one weber in terms of tesla and square metre.
Model answer
One weber equals one tesla multiplied by one square metre (1 Wb = 1 T m²).
- 2
Define magnetic flux linkage for a coil.
Model answer
Magnetic flux linkage is the product of the magnetic flux through the coil and the number of turns: flux linkage = NΦ.
- 3
Calculate the flux linkage when number of turns = 910, magnetic flux = 0.0031 Wb.
Model answer
Flux linkage = 910 × 0.0031 = 2.82 Wb.
- 4
State Faraday's law of electromagnetic induction.
Model answer
The magnitude of the induced e.m.f. is equal to the rate of change of magnetic flux linkage.
- 5
State Lenz's law.
Model answer
The direction of an induced e.m.f. or current is such as to oppose the change producing it.
- 6
Write the equation for induced e.m.f. that combines Faraday's and Lenz's laws, and explain the significance of the negative sign.
Model answer
ε = −Δ(NΦ)/Δt. The negative sign indicates that the induced e.m.f. opposes the change in flux linkage.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Electromagnetism, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.