1. Light bulbs investigation Light bulbs investigation
Practical activity
NViz Music Power 3 Gig energy
SS1
Light bulbs investigation
Light bulbs investigation
Light bulbs investigation
These bulbs all work from a 12 V supply. They all are ‘rated’ at about 20 W. Your task is to compare their energy transfer efficiency
These bulbs all work from a 12 V supply. They all are ‘rated’ at about 20 W. Your task is to compare their energy transfer efficiency
PRACTICAL Hints
Use the SEP Energy meter (or an ammeter/voltmeter/stopclock combination).
Connect a lab pack [set to 12 V] to the input side of the Energy meter.
Connect light bulb to the output side of the Energy meter.
Press the reset button.
Switch on the light, then press start, and record the total energy transferred in 60 seconds while the light is on.
Record: current, potential difference (voltage) from the Energy meter and the reading on the ‘light meter’.
Copy and fill in the table and compare the size of the energy transfers.
PRACTICAL Hints
Use the SEP Energy meter (or an ammeter/voltmeter/stopclock combination).
Connect a lab pack [set to 12 V] to the input side of the Energy meter.
Connect light bulb to the output side of the Energy meter.
Press the reset button.
Switch on the light, then press start, and record the total energy transferred in 60 seconds while the light is on.
Record: current, potential difference (voltage) from the Energy meter and the reading on the ‘light meter’.
Copy and fill in the table and compare the size of the energy transfers.
To compare the light output of the lamps, use either a light meter OR a PV cell connected to a voltmeter. This gives a reading that is a measure of the brightness of the light bulb.
To compare the light output of the lamps, use either a light meter OR a PV cell connected to a voltmeter. This gives a reading that is a measure of the brightness of the light bulb.
Light
Current (A)
Pot. dif. (V)
Joules in 1 min
Light meter reading
Filament lamp
Halogen lamp
LED lamp
Light
Current (A)
Pot. dif. (V)
Joules in 1 min
Light meter reading
Filament lamp
Halogen lamp
LED lamp
Bulbs can get hot
Bulbs can get hot
Activity from the nViz unit © upd8 wikid, built by cracking science 2009
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