# Electric and Magnetic Fields.

22 Aug  English: Fleming’s left hand rule shows the direction of the thrust on a conductor carrying a current in a magnetic field. (Photo credit: Wikipedia)

 Statement Spec ref Comments explain what is meant by an   electric field and recognise and use the expression electric field strength E   = F/Q 83 draw and interpret diagrams using   lines of force to describe radial and uniform electric fields qualitatively 84 use the expression F = kQ1Q2/r2,   where k = 1/4πε0 and derive and use the expression E = kQ/r2   for the electric field due to a point charge 85 investigate and recall that   applying a potential difference to two parallel plates produces a uniform   electric field in the central region between them, and recognise and use the   expression E = V/d 86 investigate and use the   expression C = Q/V 87 recognise and use the expression W   = ½ QV for the energy stored by a capacitor, derive the expression   from the area under a graph of potential difference against charge stored,   and derive and use related expressions, for example, W = ½ CV2 88 investigate and recall that the   growth and decay curves for resistor–capacitor circuits are exponential, and   know the significance of the time constant RC 89 recognise and use the expression Q   = Q0 e−t/RCand derive and use   related expressions, for exponential discharge in RC circuits, for example, I   = I0e−t/RC 90 explore and use the terms   magnetic flux density B, flux Φ and flux linkage NΦ 91 investigate, recognise and use   the expression         F = BIl   sin θ and   apply Fleming’s left hand rule to currents 92 recognise and use the expression F   = Bqv sin θ and apply Fleming’s left hand rule to charges 93 investigate and explain   qualitatively the factors affecting the emf induced in a coil when there is   relative motion between the coil and a permanent magnet and when there is a   change of current in a primary coil linked with it 94 investigate, recognise and use   the expression ε = −d(NΦ)/dt   and explain how it is a consequence of Faraday’s and Lenz’s laws 95