IB Prized Writing Sevenoaks School IB Prized Writing 2014 | Page 24

Robert Cinca - Physics The relationship was tested experimentally with two different filament bulbs, using the circuit seen in Figure 1. By varying the resistance in the circuit, I adjusted the The with two different bulbs, using final relationship current and was was tested able to experimentally measure the surge current times filament for different final the circuit I seen in Figure By varying the using resistance in the and circuit, I adjusted the currents. recorded all my 1. measurements a voltage current data logger, final current and (a was able to program), measure the surge for against different final thus and data studio computer which let current me plot times current time, currents. I recorded all my measurements enabling me to measure the surge current using time. a voltage and current data logger, and data studio (a computer program), which let me plot current against time, thus An excel me spreadsheet was used to see if the filament bulb can be effectively enabling to measure the then surge current time. 4 modeled as a hot body radiator . The power, , radiated by the filament is given by: An excel spreadsheet was then used to see if the filament bulb can be effectively modeled as a hot body radiator 4 . The power, , radiated by the filament is given by: (Where is the emissivity of tungsten, is Stefan-Boltzmann’s constant, is the surface area of the filament, and is the temperature of the filament in Kelvin. (Where is the emissivity of tungsten, is Stefan-Boltzmann’s constant, is the surface area of the filament, and is the temperature of the filament in Kelvin. 4 “Emissivity”, Higher Level Physics (Hamper, 2009) p298 4 “Emissivity”, Higher Level Physics (Hamper, 2009) 23 p298 5