Announcements for Physics 411 (Prof. Agashe) - Fall 2014


(1).  Note that HW 12.5 has been moved to HW 13.


(2). HW 13 has been assigned here and is due by 5 pm. outside Rm. 3118 of PSC  on Thursday,  December 11.


(3). HW 11 has been graded and solutions have been posted here (and # 12, 13 will also be done soon).


(4). Course evaluations are due by December 14 here.


(5). Final exam is on Monday, December 15, 8-10 am. in Rm. 1402.


(i).  It will cover all HW’s (#2-13), i.e., chapters 2-11 (except for parts that I did not discuss in lecture).


However, momentum in EM fields (including Maxwell stress tensor), i.e,, section 8.2, will not appear on the exam

(even though I did do it in lecture and assigned HW on it).


(ii)  The exam will have 6 problems, each with several parts, just like 1st and 2nd exams.


(iii) It will a closed book/notes exam, but most math and physics formulae you will need will be given on cover sheet of exam (a sample one is

posted here). No other formula sheet  will be allowed.


As usual, you are of course supposed to know what the meaning of each symbol in a formula is, i.e., there will not be any explanation given on this sheet,  e.g., H is auxiliary field or whether a given area element is for spherical or cylindrical coordinates.


In addition, simple math formulae such as integral of 1 / x is log x etc. will be assumed to be known to you.

Note that the formulae in actual exam cover sheet might be (slightly) different: so the main point of above sample is to just give you an idea.


(iv) Please read the (usual) instructions which appear on (sample) cover sheet carefully before you come to the exam.


(v) A review of topics and formulae (with explanation) is given here. Again, you cannot bring the above sheet to the exam.


(vi). A review session is scheduled for Friday, December 12 from 3 to 5 pm. in Rm. 3150 of PSC. I plan to go through the following list of problems during this session: HW 13.6 [which is based on example 11.2 (b) and problem 11.10/11.12 from 3rd/4th edition of Griffiths];

HW 13.1 (problem 9.31/9.32 from 3rd/4th edition of Griffiths); HW 4.4 (problem 3.6/3.7 fro 3rd/4th edition of Griffiths); HW 6.3; problems 3 and 4 from 2nd midterm; example 6.3 from Griffiths and HW7.1 (problem 5.3 from Griffiths).


(6). Outline of plan for last 4-5 weeks of lectures is to study an application of Maxwell's equations, namely, EM waves:


(i) we will begin with conservation and flow of energy/momentum in EM fields (eventually in these waves): sections 8.1 and 8.2 (but I will skip angular momentum, section 8.2.4).


(ii) Next, we will study propagation of waves (chapter 9), followed by


(iii) how to solve for potentials (and fields) with time-dependent charge/current densities (in general) from chapter 10 and


(iv) finally, apply the techniques from chapter 10 to a specific time-dependent charge/current configuration which creates EM waves (chapter 11).


Note that we will skip some (actually, many in some cases) parts in chapters 9-11 as well (I'll give you more details as we go along)!


(7). More detailed  plan for lectures for weeks just before/after Thanksgiving:




(i) warming-up (section 9.1) with waves in 1 dimension (e.g., on string), we have started 


(ii) propagation of EM waves (in 3 dimensions) in vacuum (section 9.2): we'll first do plane waves 

(sections 9.2.2 and 9.2.3). Then we will consider 


(iii) EM waves in matter (section 9.3), including what happens when waves cross a boundary (sections 9.3.2 and 9.3.3). 


We will skip section 9.4 (EM Waves in conductors). Then, 


(iv) we come back to EM  waves in vacuum, but this time confined ("guided") ones (section 9.5), including rectangular wave guide (section 9.5.2)

and coaxial transmission line (section 9.5.3)


(8). More detailed plan for last week and half of  lectures:


(a). First, we will study how to calculate fields with time-dependent sources (in general):


(i) We will introduce potential formulation for this purpose (section 10.1).


(ii) We will then compute potentials for continuous change distributions (section 10.2).


We will skip the case of point charges (section 10.3).


(b). Next, we will consider radiation, i.e., how EM waves are created:


(i)        introduce the general idea (section 11.1.1) and


(ii)      derive radiation of EM waves (including the associated power) from an oscillating electric dipole (section 11.1.2) and use this example to “justify” the general formula for power radiated in Eq. 11.60 (from section 11.1.4)


Note that we will skip magnetic dipole radiation (section 11.1.3) and that from point charges (section 11.2).


(9). The schedule/location of office hours is as follows (they are also listed on course webpage):


(i)        By instructor:


 Tuesday 2-3 pm. in Rm. 3118 of PSC


                 Thursday 1-2 pm. in Rm. 1304 of Toll building


(ii)      By TA:


Monday: 1-2 pm. in Rm. 1304 of Toll building


Wednesday: 1.45-2.45 pm. in Rm. of  3101 of Toll building


Please note location and day carefully. The ones in Rm. 1304 of Toll building (which is actually a small classroom) will be sort of informal discussion sessions, i.e., you are not required to attend them, but it will be useful to do so!



(10). 2nd midterm exam scores (out of a maximum possible of 40): average 32, with standard deviation of 8 .Solutions have been posted here.


(11). 1st midterm: solutions are posted here. Average was 32 (out of maximum of 40), with a standard deviation of 9.5.