1:06:15

wave motion part 1 (1 _ 40)

43:32

thin prism

58:10

lesson 4 (deviation through triangular prism)

32:15

ch 1 lesson 1 part 1 (Q1 _ Q18)

46:27

minimum deviation

1:23:48

ch 2 lesson 3 (total internal reflection)

1:28:45

ch 2 lesson 1 (light properties)

2:09:11

ch 1 lesson 2 part 6 (ammeter and voltmeter reading)