(b) any one from it does not stay magnetised • it can be turned off • accept cannot turn steel ‘you off’ objects do not stay attached to it • iron loses its magnetism • steel stays magnetised • 1 (L6) (c) (i) any one from the greater the distance the lower the • reading the further away the smaller the reading • accept the converse accept distance the field is ‘at big or the converse weaker’ accept mm the reading is ‘at 50 lower’ accept the converse not do accept bigger the ‘the distance the smaller the ampsor current’ 1 (L6) (ii) the greater the current the stronger • the electromagnet 1 (L6) (iii) any one from change the number of turns • change the thickness of the wire • change the diameter of the core • accept more ‘use coils’ accept fewer or less ‘use coils’ accept the coils closer ‘put or the converse together’ accept the metal of the ‘change coils’ accept a ‘use different sized core’ accept nickel or cobalt ‘use core’ accept a different ‘use core’ bigger is insufficient ‘use coils’ more is insufficient ‘use wire’ not do accept more ‘add batteries’ 1 (L6)
(b) any one from • it does not stay magnetised • it can be turned off accept ‘you cannot turn steel off’ • objects do not stay attached to it • iron loses its magnetism • steel stays magnetised 1 (L6) (c) (i) any one from • the greater the distance the lower the reading • the further away the smaller the reading accept the converse accept ‘at big distance the field is weaker’ or the converse accept ‘at 50 mm the reading is lower’ accept the converse do not accept ‘the bigger the distance the smaller the ampsor current’ 1 (L6) (ii) • the greater the current the stronger the electromagnet 1 (L6) (iii) any one from • change the number of turns • change the thickness of the wire • change the diameter of the core accept ‘use more coils’ accept ‘use fewer or less coils’ accept ‘put the coils closer together’ or the converse accept ‘change the metal of the coils’ accept ‘use a different sized core’ accept ‘use nickel or cobalt core’ accept ‘use a different core’ ‘use bigger coils’ is insufficient ‘use more wire’ is insufficient do not accept ‘add more batteries’ 1 (L6)