add an extra exercise

ae2a5395 · Anton Akhmerov · d20cf8e9 · ae2a5395
Commit ae2a5395 authored 6 years ago by Anton Akhmerov
--- a/docs/index.md
+++ b/docs/index.md
@@ -34,7 +34,7 @@ If something is unclear, if you notice a typo, or if you have a suggestion, plea

 * Week 8: [Magnetism](lecture_8.md)  
  (based on chapters 19-20)  
-  Exercises 19.3, 19.6, 20.1, 20.4
+  Exercises 19.3, 19.6, 20.1, 20.2, 20.4

 ## Test results