Lab+Report+5

Hey that looks great but is all the work added? I see all of the equations and stuff but I dont wanna get points off for not having work again  I actually did this lab before I withdrew last time, if you open the document above it has everything except maybe a bit more of a conclusion. I updated it and all it needs is that conclusion and names. **__ Int __** **__ roduction __**  For this experiment, the objective was to learn to utilize a Wheatstone Bridge to measure resistances and investigate some of the properties of the resistance of wires. After, the bridge was used to find the value of an unknown resistance. According to the text, the resistance of a conducting wire depends on its physical properties, such as the material making it up, it’s length, and the cross sectional area. This can be determined by the following expression: R = p * (L/A) where R is resistance, p is the resistivity of the material, L is the wire’s length, and A is the cross sectional area. Furthermore, for this experiment all of the resistors obey Ohm’s Law (V = I * R). Finally, Kirchhoff’s Laws were used in the determination of voltages and currents in the circuit.



In this experiment we change things up by inserting the unknown resistance into a circuit and measuring R by its effect of the circuit, through the Wheatstone bridge. One shall use the Wheatstone bridge apparatus with the power supply (dc) and the galvanometer. Connect the circuit as shown in the given figure using the unknown resistance as the slidewire that is on top of the meterstick. The highter the voltage one uses the better the results will turn out for the measurement, but of course be careful not to use too much power. To not overload on the current, measure the resistance of the entire length of the wire with the digital multimeter and have the contact 50 cm above the unknown resistance and measure the resistance of this length. Next insert the given resistors into circuits R1 and R2 and the variable resistor box to R3 to determine the value of R3. The value of R3 is necessary to balance the circuit. The amplitude should be on complete zero and connect the power supply and press the lever to touch the slidewire to the circuit. From that record your reading. While the lever is held down, adjust R3 so that the galvanometer is zero. To increase accuracy, turn up the voltage across the circuit. Put the multimeter across the output of the pwer supply, adjust the voltage to .2V and balance the circuit. Finally record the values of R3 while balanced and plot a graph of R3 vs. L and repeat the measurements. The graphs should all be a straight line if done correctly.
 * __ Procedure: __**