1. Type of bulb Energy (J) Stated
power (w)
Time (s) Actual
Power (w)
(2dp)
Florescent 1 1000 9 49.26 20.30
Florescent 2 1000 11 16.11 62.07
Filament 1 1000 25 38.15 26.21
Filament 2 1000 150 7.30 136.99
Filament 3 1000 40 24.41 40.97
Filament 4 1000 10 89.88 11.12
Filament 5 1000 100 10.46 95.60
Filament 6 1000 40 23.94 41.77
Filament 7 1000 60 16.11 62.07
Actual power calculated using
the formula :
Power = energy (j) / time (s)
PART A

2. Type of
bulb
Stated
power
Actual
power
Tolerance
(%)
Filament 10 11.12 +1.12
Filament 25 26.21 +4.84
Filament 40 40.97 +2.425
Filament 40 41.77 +4.425
Filament 60 62.07 +3.45
Filament 100 95.60 -4.40
Filament 150 136.99 -8.67
Fluorescent 9 16.11 +79.00
Fluorescent 11 49.26 +347.82Tolerance calculated by: [actual
power (w) / stated power (w)] X
100

3. Type of bulb Stated power
(w)
Light Intensity
Florescent 1 9 36.13
Florescent 2 11 144.20
Filament 1 25 2973.63
Filament 2 150 15698.09
Filament 3 40 4982.76
Filament 4 10 1778.41
Filament 5 100 14550.93
Filament 6 40 3720.25
Filament 7 60 9821.32
PART B

4. Florescent bulbs

5. Highest value = 15698.09

6. (i) The independent variable in our
experiment was the light bulbs.
(ii) The sensitivity of the GLX was 0.01
(iii) ??????
(iv) Using the graph we can see that light
intensity depends on power. The more
power you have the higher the light
intensity. ????? What else can we put :S
PART B

7. What can we do in future?
• Plan the experiment first! Timing is
essential.
• Definitely read up on your experiment
before hand
• If you can, try and get more results so you
can have a more accurate set of results
• Draw tables before hand – saves time!

8. *Notes
* One of our florescent bulbs was broken
* Had to put our GLX on top of our books to
try and keep it in the same position for
each bulb – moving it could greatly affect
results
* Reaction times in terms of stopping the
stop watch will have affected our results.
(human error)