Physics Lab 2 RLC Circuit Oscilloscope & Function Generator

Transcription

1 Physics Lab 2 RLC Circuit Oscilloscope & Function Generator Monday 9AM-Noon Section L2T Instructor: Thomas Mattison TA s: Andrew Jacobs, Peter Gysbers

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3 Missed Labs If you know you will miss a session, or get sick, mattison@physics.ubc.ca with sessions the same week you could make, and you will be assigned to one of them You will probably form a temporary triple If your partner is missing, also a temp-triple unless there is already a triple or single We need to move to the next setup frequently When we do 2-week labs, there s a bit more possibility for makeups

4 Feedback from TA s on Lab 1

5 Lab 1 as a Parable Study instruments Quick & dirty attempt: push spring by hand Discover limitations ( noisy data) Try obvious fix: use weights Discover limitations (big weights topple spring) Try alternative: control length, measure force Much better force and distance measurements

6 Lab 1 as Practice Example of what should be in a lab notebook as a measurement is being developed Practice estimating raw data uncertainties Practice doing uncertainty arithmetic We know (now) it was too long Drop digital scale exercise Less uncertainty analysis in Method 1 Method 2 should be qualitative Focus on Method 3 data & uncertainty

7 Trial of New Overtime Policy We prefer not to rush students out the door, and instead let them continue learning A few students have complained that s unfair to them, because they have a tight schedule that doesn t allow them to stay overtime So this week, we ll enforce a 10 minute limit: If session ends at 11:50, notebooks due by 12:00 We ll see how well that works

8 L2? Family name Also on 2 hidden sides Family name L2? Partner s family, given name PHYS 159 Family name, Given name Student ID L2? of week starbng TA 1 name TA 2 name L2? Family name Family name L2?

9 Lab Notebook Rules Page 1 is reserved for a Table of Contents New entry: today, RLC Circuit, p.??, (grade-space) On first page of each week Family name, given name, date Partner name Lab topic Lab topic and date at top of each other page

10 Lab Notebook Rules (2) Attach paper plots and data tables securely You should bring your own fastening Glue-stick or tape at multiple points Rubber cement is highly recommended No staples or paperclips We supply Elmers, but it wrinkles and pages stick

11 Lab Notebook Rules (3) It s your logbook, write what you see & think You won t be marked down for writing extra stuff, even if irrelevant, like reminders to buy milk Exception: protocols should not have random stuff Random stuff is OK when logging execution of protocol It should be a permanent record Generally, write in non-erasable ink If you make a mistake or change your mind, don t scribble over it, put a box around it and make a note in the margin No white out Don t tear out pages

12 Lab Notebook Rules (4) Rationalized Pencil Rule You can START a graph or sketch in pencil But when it s right, ink over it

13 Lab 2: RLC Circuit, Oscilloscope, etc. Instrument skills with oscilloscope, function generator, multimeter, breadboard More independent lab notebook writing More practice with raw data uncertainties and uncertainty arithmetic A bit of new-ish physics

14 Lab Notebook for Lab 2 Write enough about what you are doing that you could reproduce your steps and data a month from now just from what you write, without a copy of the paper procedure There is a rubric on the web There are prompts in the procedure that match the rubric, this week, but less in the future Don t write knob-by-knob instructions You ll be familiar with the instruments in a month

15 Oscilloscope & Function Generator Work through the Triggering section of the Exercise It asks you to write some things in your lab notebook Then go to RLC Procedure Go back to Oscilloscope & Function Generator Exercise as needed

16 Breadboard Load Resistor Inductor Capacitor

17 Underneath the Breadboard

18 RLC Circuit If capacitor is charged, then circuit is closed, it discharges through inductor, but current continues to flow, causing the capacitor to reverse-charge, then reverse-discharge,. Resistor eventually damps out the oscillation

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21 Time to Finish Up Make sure your lab notebook is labeled properly, including who your partner is Both lab notebooks should be placed in the same stack in the front, consecutively Pick up your lab notebooks a week from today Pre-reading and procedures for next week will be posted on web as soon as they are ready