Filament Lamp Experiment PDF

## Filament Lamp Experiment ### Aim 1. Studying the relation between the current passing through a filament lamp and the potential difference across it. 2. Determination the values of constants $n$ and $k$. ### Theory - Any current passes through an electrical element at constant temperature obeys...

## Filament Lamp Experiment ### Aim 1. Studying the relation between the current passing through a filament lamp and the potential difference across it. 2. Determination the values of constants $n$ and $k$. ### Theory - Any current passes through an electrical element at constant temperature obeys Ohm's law as follow: $I = \frac{V}{R} = Vk$ where: - $K = \frac{1}{R}$ - called conductivity equals to the reciprocal of electrical resistance - But in the case of the current that passes through a filament lamp, the lamp is heated and the energy is continuously lost by radiation in this case - The current passes through the filament lamp do not obey Ohm's law ($I=Vk$) instead of, $I=kV^n$ - In this case, the current do not change linearly with the potential difference, but changes exponentially. - $(n)$ is a constant represents the energy loss in the form of radiation. - By taking the log for equation: $logI = logk + nlogV$ ### Setup 1. DC source 2. Rheostat 3. Ammeter & Connection leads (wires) 4. Voltmeter 5. Lamp ### Procedures 1. Connect the circuit as shown. 2. Adjust the rheostat for a suitable value and record the reading on $V$, $A$. 3. Repeat the last step for different values. 4. Tabulate your results: | $I(mA)$ | $V(n)$ | $logI$ | $logV$ | 5. Plot a relation between $I$ (Y-axis) V (x-axis) and determine the slope which represents $(n)$ and the intercept that represents $logk$ $logk \begin{array}{c} |\vspace{1.5cm}\\ |\vspace{1.5cm} \end{array} \longrightarrow logV$ $slope = n$ $\downarrow$ $logI$