Sources of error in a circuit lab

A. Equipment Setup 1. Plug the sensor cable into Analog Channel A on the Interface. Switch on the computer and the Interface. 2. Open the Capstone program and select the Magnetic Sensor icon. Select a Digits display and choose Magnetic Field. 3. Select one of the coils supplied. Connect the DC power supply, the switch, the ammeter, and the coil in series (Figure 8.5). For each coil you select, record the number of turns N. Caution. Be sure to connect the ammeter with the correct polarity. 4. Have the instructor check your circuit before you proceed. Power supply switch Ammeter B. Data Collection Figure 8.5 1. Select the axial function on the magnetic field sensor. Hold the sensor away from any source of magnetic fields and zero it. 2. Close the switch and set the power supply current to 1.0 A. Record this voltage and the exact current (to 3 sig. dig.) through the circuit. Caution. Do not leave the current on when you are not taking a magnetic field reading. 3. Click record at the bottom of the screen. 4. Insert the sensor probe into the coil. Move it to a point near the center of the coil. Measure and record (in Table 8.1) the radial magnetic field at the center of the coil. 5. Open the switch, remove the sensor from the coil, and click the Stop button. 6. Repeat steps 1-5 for currents of 2.0 A, 3.0 A, 4.0 A and 5.0 A. Do not allow the current in the circuit to exceed 5A. 7. Measure and record the length L of the coil. 8. Repeat steps 1-7 for a second coil. Be sure to record your data for the second coil in Table 8.2. C. Data Analysis 1. For each coil, plot a graph of magnetic field magnitude B vs. current I. From the slope of your graph, calculate and record the number of turns N in the coil (round to the nearest integer). 2. each coil, calculate and record the percent rence between your calculated value of N and the value printed on the coil.