Candidates showed improvement in the:
          -    tabulation of data obtained
          -    recording of measured and calculated values to the required number of decimal places
          -    plotting of graphs using correct and suitable scales
          -    stating of precautions in appropriate and acceptable language
          -    listing of examples of Non-ohmic conductors
          -    calculation of critical angle using the formula  n =    
          -    listing of four applications of plane mirror
          -    determination of I from the graph when d = 90cm and the value of L corresponding to   t = 12s