Download DC Circuits Lab Report: Physics 212P-6 and more Lab Reports Physics in PDF only on Docsity! Physics Lab 212P-6 DC Circuits NAME: ____________________________________ LAB PARTNERS: ____________________________________ ____________________________________ LAB SECTION: __________________________ LAB INSTRUCTOR: __________________________ DATE: __________________________ EMAIL ADDRESS: __________________________ Physics Lab 212P-6 Software list N/A Equipment List (all items marked with * are in the student kit, others are supplied at the time of the lab) Digital multimeter + probes *Two 1.5 V batteries + a battery holder *Flashlight bulbs (2 round, 2 long) + bulb holders *Hookup wires with alligator clips *Compass Q5. Why is there a discrepancy between the EMF of each battery measured before the circuit is completed and after the circuit is completed? Think about the fact that these are real (and not ideal) batteries. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Q6. Creative exercise: Explain why the bulbs behave as observed when the circuit is completed. Use the idea that a given bulb needs to dissipate a certain minimum amount of power to light up. (Why?) Note again that you do not know the resistance of the bulbs when they light up, but it is safe to assume that the DMM correctly tells you which bulb has a smaller resistance even when they light up. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Lab Activity 2: Resistors in Parallel Q7. Draw a circuit diagram representing the circuit shown above. Note that one of the bulbs is round and the other one is long (i.e. they have different resistances). As in activity 1, assume that the batteries are NOT ideal. Connect the above circuit and use the DMM to record the potential difference VC-VD. Unscrew the ROUND bulb from its socket, leaving the rest of the circuit intact. Carefully observe the brightness of the LONG bulb while you do this. Again, record the potential difference VC-VD. Q8. Did the potential difference VC-VD change when you unscrewed the round bulb? Did the brightness of the long bulb change slightly when you unscrewed the short bulb? _____________________________________________________________________________ _____________________________________________________________________________ Q9. Explain why your observations in Q8 clearly indicate that the batteries are non-ideal. _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ Q10. Creative exercise: develop an analytical argument that proves that -- if the batteries are not ideal -- then the brightness of the long bulb must increase when the round bulb is removed. .
