EXETER UNIVERSITY PHYSICS PART I EXAM PAPER CXXXIX TIME - ALL DAY HONOURS PHYSICISTS ANSWER ANY FIVE QUESTIONS HONOURS THEORETICAL PH. ANSWER ALL QUESTIONS HONOURS MEDICAL PH. ANSWER ANY FOUR QUESTIONS HONOURS ELECTRONCS PH. ANSWER ANY EASY QUESTIONS HONOURS GEOLOGICAL PH. ANSWER ANYTHING! HONOURS COMBINED PH. ANSWER ALL QUESTIONS TAKING HALF THE TIME! The questions are to be attempted, crossed out, re-attempted, screwed up and thrown away. Slide rules won't help you try a calculator. If that doesn't work, CHEAT. (MARKS- Some more than others, we're not telling which. The numbers at the end of a question are only there to confuse you.) Data from the following list is only of any use if you are a girlie swot: Accelaration of free fall g=10m/s/s Permittivity of blancmange Eb = (approx.) 6.12358974562310256489 * -12 Height of the Eiffel tower H =325m Speed of sound in a vacuum s = 0.0000000000 Chance of you passing C = 0.0001 Answer to question 4(a) A = 12000 --------------------------------------------------------------- 1. State the principle of least work and show how this can be used to good effect before, during and after lectures on a monday morning. Hence, or (if you are stupid) otherwise show how the principle fails to produce any encoraging 'phone calls home to parents when the exam results are published. 2. Describe an experiment you haven't done, quoting the wrong formulae and guessing the rest. Plot a few graphs (looks impressive, sure to gain marks!). Mention Newtons laws of something and conservation of the Giant Panda. This question must take at least three quaters of your exam time. 3. In this experiment the plates are 1.5" apart (we don't have to use S.I. units but YOU DO ) with zero potential between the plates. A charge of mass 8.0 -16 kg falls with velocity 4.0 -5 N/S. When a potential difference of 75 volts is applied across the plates all the sawdust moves about. Given the charge on an electron (C) is -1.6 -19 kg , how high is the Eiffel Tower? 4. Using the Boltzmann constant and Einstein's photo electric equation :- (a) Stare out of the window, worrying about how to tell your parents why everybody else passed with over 90% and you only got 3%.(And that was for spelling your name correctly) (b) Do the bit of question seven that makes sense, give up and doodle uncontrollably on the rest of the paper for 45 minutes. ------------------------------------------------------------------- When you have finished, sit with your arms, legs and other appendages, folded wishing you'd done more revision, whilst the clever people ( who still manage to sit at the front even though you sit in alpha- betical order) ask for more paper. If you like , please attach a signed cheque for over 100 pounds made payable to CASH.