Module 6: Particles and medical physics

6.3 Electromagnetism

6.3.1

Magnetic fields

(a) magnetic fields are due to moving charges or permanent magnets

(b) magnetic field lines to map magnetic fields

(c) magnetic field patterns for a long straight current-carrying conductor, a flat coil and a long solenoid

(d) Fleming's left-hand rule

(e) (i) force on a current-carrying conductor;

F = BI L sin θ

(e) (ii) techniques and procedures used to determine the uniform magnetic flux density between the poles of a magnet using a current-carrying wire and digital balance

(f) magnetic flux density; the unit tesla.

6.3.2 Motion of charged particles

(a) force on a charged particle travelling at right angles to a uniform magnetic field;

F = BQv

   

(b) charged particles moving in a uniform magnetic field;

circular orbits of charged particles in a uniform magnetic field

  Learners will also require knowledge of 3.2, 3.3 and 5.2

(c) charged particles moving in a region occupied by both electric and magnetic fields; velocity selector.

   

6.3.3

Electromagnetism

(a) magnetic flux φ;

the unit weber;

φ = BAcosθ

   

(b) magnetic flux linkage

   

(c) Faraday's law of electromagnetic induction and Lenz's law

   

(d) (i) e.m.f. = − rate of change of magnetic flux linkage;

   

(d) (ii) techniques and procedures used to investigate magnetic flux using search coils

   

(e) simple a.c. generator

   

(f) (i) simple laminated iron-cored transformer;

for an ideal transformer

   

(f) (ii) techniques and procedure