Summary PHY 114 Lab Report 4: Physics of a Light Bulb. Arizona State University

Lab Report 4: Physics of a Light Bulb

PHY 114

, ABSTRACT:

The objective of this lab was to understand and be able to compare the relation between voltage

and current in a small flashlight bulb and to verify the Stefan Boltzmann law of radiation. By

using a circuity involving a DMM, a DC power supply, a light bulb, and a computer interface

with voltage sensors, several plots were made to help determine specific values in the circuit. An

internal resistance of 2.67 Ohms was found on the filament of the bulb. The Stefan-Boltzmann law,

P=A*T^4, says that power output increases exponentially by a power of 4 with increasing temperature.

The graph should be linear and the slope should represent the exponential increase of power by 4. An

experimental linear slope of 3.8 is 5% off of the theoretical value of 4, a negligible error. The Stefan-

Boltzmann law was validated and the lab was completed successfully.

OBJECTIVE:

The objective of this lab was to understand and be able to measure the relation between voltage

and current in a small flashlight bulb and to determine the temperature of the filament. This is all

done to try to validate the Stefan-Boltzmann law of radiation.

PROCEDURE: