Scheme
____________________________________________________________________________________
AQA
A- LEVEL PHYSICS MARK SCHEME
WITH DETAILED AND CORRECT
ANSWERS
_______________________________________
Line of force
, ✓ Direction a hypothetical "free north pole" would travel in the field. Otherwise known
as a field line.
Motor effect
✓ Effect in which a current in a magnetic field experiences a force.
Fleming's left hand rule
✓ Way of working out the directions involved in the motor effect.
Magnetic flux density
✓ Force per unit length per unit current on a conductor perpendicular to the field lines.
Often referred to as the strength of the magnetic field.
Couple
✓ Pair of forces in opposite directions that try to turn an object. Acts on the coil of a
motor.
Thermionic
✓ Property of a material that means that when it gets hot, it emits electrons.
Cyclotron
, ✓ Spiral particle accelerator.
Frequency
✓ Number of rotations per second, given by 1/T.
Mass spectrometer
✓ Device that separates a constituents of a substance by their masses.
Ion
✓ Charged atom.
Velocity selector
✓ Component that uses an opposing electric and magnetic field to ensure all particles
going straight through have the same speed and direction.
Vacuum
✓ Space where (nearly) all particles have been removed (evacuated).
Electromotive force
✓ Force on electrons that tries to push them along. Known as the emf.
Electromagnetic induction
, ✓ Phenomenon in which a changing magnetic field, relative to a wire, will produce an
emf.
Fleming's right hand rule
✓ Also known as the dynamo rule. Works out directions involved in electromagnetic
induction.
Solenoid
✓ Electrical coil.
Lenz's law
✓ "The direction of the induced current is always such as to oppose the change that
caused the current".
Magnetic flux
✓ Product of the magnetic flux density and the area.
Magnetic flux linkage
✓ Product of the magnetic flux and the number of turns of the coil.
Faraday's law