8/14/2019 Paper 4 Jun 1999 Physics

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Answer guide for O Level Physics (5054/4) Paper 4 Alternative to Practical June 1999

Page 1 of 2 UCLES 2002

1(a) Any three from:

Make sure the rule is parallel to the stationary thread

Use a second clamp to hold it steady

Use a small ruler at right angles to the rule in line with thecentre of the bob and the lower point of the clamp or

attach a

pointer at each position (or show on a diagram)

Calculate the difference of the two readings 3

(b) The stopwatch is not sufficiently accurate/ has an uncertainty of 0.1

s / it would have read T = 1.0 s / There is a reaction time in starting

and stopping. 1

20 swings takes longer so the time is more accurately measured / it

would read t = 20.6 s so T = 1.03 s 1

(c) 1 : 46 . 6 1

2(a) 0.02 1

0.4 1

(b) Y 1

The maximum current is 0.4 (A) / it would be more accurate 1

(c) Remove the thermistor from the oil, the current changes very little

or Disconnect the thermistor, the current falls to almost zero 2

3(a)(i) 11.5 / 14.5 = 0.79 or 0.8 2

(ii) 1/5 or 0.2 1

(b)(i) The ball would not bounce 1

(ii) All of its energy is transferred to the glass 1

(c) Volume / mass 1

8/14/2019 Paper 4 Jun 1999 Physics

2/2

Answer guide for O Level Physics (5054/4) Paper 4 Alternative to Practical June 1999

Page 2 of 2 UCLES 2002

4(a)(i) F

A

= 4.5 (units not essential)

F

B

= 1.9 1

(ii)

A

/B

= 2

F

A/ F

B

= 2.37 1

(iii) The rate of cooling is greater at greater excess temperature 1

The excess temperature and rate of cooling are proportional / When

the excess temperature doubles the rate of cooling increases by 2.37

times 1

(b) All points lie on a smooth curve / short period of time 1

(c) To avoid draughts 1

5(a) Correcty

-axis and sensible scale 1

Correctx

-axis and sensible scale 1

Accurate plotting (5 points) 2

(4 points) (1)

Best straight line, neat, thin and with good judgement 1

(b) One of :

Have the rule close to the lens and screen

Use a set square to line up the lens / screen with the rule or similar 1