Answers to KS3 level 3 questions

1.       (a)     mirror or something shiny                                                                                    1

accept ‘reflector’ or ‘her watch’
or any named shiny object

do not accept ‘torch’ or any named light source

(b)     reflects them                                                        accept ‘bounces the light off’                   1

[2]

2.       (a)     answers should indicate that the circuit is incomplete

         any one from                                                                                                     1

·   the circuit is not complete              accept ‘the circuit is broken’

·   there is a gap in the circuit             do not accept ‘the bell is not connected’

·   the wires are not joined                 do not accept ‘current or electricity
or connected                                 cannot get through’

(b)     answers should indicate that the circuit is now complete

         any one from                                                                                                     1

·   the circuit is complete                    accept ‘the current can flow all the
                                                    way round’

·   there is no gap in the circuit            do not accept ‘current can flow’

·   the wires are joined or connected   accept ‘electricity can go through the pin’

·   steel is a conductor

(c)     any one from                                                                                                     1

·   wood is an insulator                       accept ‘electricity cannot go through wood’
                                                    or ‘wood is a non-metal’

·   the matchstick does not conduct electricity

(d)     any one from                                                                                                     1

·   rust is an insulator                          accept ‘rust stops the electricity flowing’

·   rust does not conduct electricity      do  not accept ‘the steel pin does not
                                                    conduct electricity when it is rusty

·   rust stops contact being made

(e)                                                                                                                              4

if more than one line is drawn from the same part of the car, award no mark for that part

(f)      any one from                                                                                                     1

·   by electricity

·   along the wires                              accept ‘from the battery’ or ‘by electrons’

[9]

         3.

award a mark for each correct line

if more than one line is drawn from any item,
or to any fuel, deduct one mark for each extra line; minimum mark zero

accept central heating boiler ------  coal

accept central heating boiler ------  gas

accept fireplace  --------------------  gas

[3]

4.       (a)     (i)      vibrating                                if more than one box is ticked,                 1
                                               award no mark

(ii)     any one from                                                                                            1

·   as a wave                            accept ‘by vibrating air’

·   through the air

·   in a straight line

(iii)     ear drum                                  accept ‘drum’ or ‘cochlea’

(b)     (i)      It sounds quieter than before       if more than one box is ticked,            1
                                                    award no mark

(ii)     It has the same pitch as before    if more than one box is ticked,            1
                                                    award no mark

[5]

5.       (a)     B                                                                                                                       1

(b)     D                                                                                                                       1

(c)     (i)                                                                                                                      1

one mark for the arrow pointing to the left the arrow may be anywhere on the diagram

accept ‘D’ on the diagram

accept arrows pointing diagonally downwards and to the left

do not accept arrows pointing vertically downwards

(ii)     answers should refer to a force pulling or the effect of pulling

any one from                                                                                            1

·   because Megan is pulling it

·   because there is a force on it

·   because the force is unbalanced

·   force D is still acting

accept ‘because it was stretched’ or ‘because the dog isn’t pulling it any more’

accept answers referring to gravity, weight or falling only if the arrow in (c) (i) points diagonally or vertically downwards

do not accept ‘it is not attached to the dog any more’

[4]

6.       (a)     A                                                                                                                       1

(b)     (i)      the centre of a cross (X)           do not accept the centre of the cross        1
drawn in the shaded area          below the water line or above the
     between boats A and B        shaded area

(ii)     any one from                                                                                            1

·   light cannot go through the boat

accept ‘the boat is opaque' or ‘the boat absorbs or blocks or stops or reflects the light'

·   light travels in straight lines

accept ‘light cannot bend round the boat'

(c)     E                                                                                                                       1

(d)     the reflected ray touches the                                                                               1
incident ray at the surface of the mirror