We did a revision quiz which was won by A.M. and did some personal revision.
Homework
Revise for mock. Solutions to exam questions in book are here.
Test Feedback
Classwork
We went over the end of topic test.
Homework
Revise for mock exam next Thursday.
Test
Classwork
We did a test on chapters 12 and 13. Results next lesson.
Homework
No homework.
Finished Syllabus
Classwork
We reched the end of the syllabus and did some circuits questions for fun.
Homework
Revise for test on chapters 12 and 13 next Wednesday.
Diffraction gratings
Classwork
We saw the diffraction pattern produced by a diffraction grating, and calculated the maximum order for a given grating spacing and wavelength.
We used spectroscopes and a spectrometer to observe various emission and absorption spectra.
Homework
Answer Q.1-4 on P.207. Check the answers in the back of the book. Hand in tomorrow morning.
Reminder: test next Wednesday.
Single slit pattern
Classwork
We deduced the wavelength of a laser from the double slit pattern it produced.
We looked at single and double slit diffraction patterns, and the effect of having the slit separation and slit width of a doulbe slit too small in comparison to the distance to the screen.
Homework
Watch this video which shows you the pattern produced by a diffraction grating, and read P.205-6 of AQA. Notice how the pattern differs from a double slit pattern.
Watch this video which derives the diffraction grating formula d sinθ = nλ.
Make notes on this and bring any questions you have to next lesson. Next lesson we'll look at the diffraction pattern produced and see some uses for diffraction gratings.
ADVANCE WARNING: there will be a test on chapters 12 and 13 on Weds 19th March.
Double slit interference
Classwork
We saw the limitations of the fringe spacing formula when D is not greater than s, discussed coherence and the interference patterns produced by monochromatic and white light.
Half the class started to deduce the wavelength of light from a laser using a two slit interference pattern - we will finish this next lesson.
Homework
Read p.199-201 and add any extra details to your notes. Bring any questions you have to next lesson.
Answer Q.1,3,4 (NOT 2) on P.201 and hand in tomorrow morning.
Try to make and test the double pinhole the guy talked about in the video from last Wednesday. THERE IS NO NEED TO USE ANYTHING SHARP OR DANGEROUS - just make two dimples in the metal sheet using a biro and sand the dimples until they become small holes.
Two source interference
Classwork
We observed diffraction of light through one slit and two slits, and interference of sound from two sources.
We covered key terminology (fringe separation, slit separation, etc etc) for Young's double slits, and got a feel for the formula w = λ D / s
Homework
Read P.197-8 of the textbook and watch either this video or this video (or both, or any other video you find that is better) and make notes. You do not need to be able to derive the formula w = λ D / s but it is good to see where it comes from.
Answer Q.2-4 on P.198 and check your answers in the back of the book. This basically just involves plugging numbers into the equation above, but take good care with units. Bring your notes and answers to next lesson.
At some point before the next lesson, try to make and test the double pinhole thing the guy talked about in the video from Wednesday. THERE IS NO NEED TO USE ANYTHING SHARP OR DANGEROUS - just make two dimples in the metal sheet using a biro and sand the dimples until they become small holes.
ALSO you may want to have a play around with this refraction and TIR simulation to get a feel for how the critical angle depends on the refractive index of the two materials.
Total internal reflection, interference
Classwork
We checked results tables and graphs from TIR experiment and discussed coherent bundles of optical fibres.
We looked at a couple of demonstrations of TIR in water streams - hopefully we can improve this next lesson.
Watch this video about the Cornell note taking method (start at 1:04).
Read P.196-7 of AQA and watch this video about Young's double slit experiment.
Use the Cornell note taking method to record your notes and bring them to tomorrow's lesson.
Don't bother making notes about the historical stuff (unless you really want to!) and also don't be put off by the complicated sounding maths - we don't quite go into that depth at AS.
BRING A COAT to tomorrow's lesson - we may go out to the field.
We discussed dispersion (remember Blue Bends Best).
We derived the critical angle formula and looked at total internal reeflection in optical fibres.
Homework
Read P.193-4 and answer Q.1-3 on P.195. Bring to tomorrow's lesson.
Refraction
Classwork
We marked the homework questions and discussed the first demonstration from the video from the homework.
We briefly recapped on Snell's law, which was covered at GCSE - if you want more of a reminder watch this video.
We did this experiment to find the refractive index of a perspex block.
Homework
Plot a graph of sin(i) against sin(r) and find the gradient to determine the refractive index of the block.
Answer Q.2-4 on P.189 of AQA and hand in on Monday.
Standing waves
Classwork
We did four of the standing waves experiments here - standing waves in an air column, standing waves on a long spring, standing waves on a rubber sheet and standing waves on a monocord.
Complete investigation 1 and hand in your completed results table and conclusion on Monday.
Answer Q.1-2 on P.183 of AQA and hand in on Monday.
Read about different standing waves experiments here and vote here for which one you want to see next week. YOU MUST DO THIS TONIGHT SO I CAN REQUEST EQUIPMENT FOR NEXT WEEK.
Superposition, standing waves
Classwork
Phase difference (video from last HW) - found phase difference between these waves.
Wave superposition and then found the resultant waves on the other side of the above sheet.
Homework
Read P.176-7 of the AQA textbook to recap on key terminoligy and the formulae T = 1/f and c = fλ (we will need these next lesson).
