36:37

Ch 21 Electric Current P2

25:53

Electromagnetism P1

30:12

Ch 20 Electricity

23:01

CH 20 Electricity P3

21:27

Ch 22 Electromagnetism P2

18:44

Ch 16 Sound And Music p1

19:49

Ch 18 Refraction Of Light P1

12:30

Ch 20 Electricity P2