A student is using a frequency generator set to 440 Hz. Another student has an identical generator playing an unknown frequency. When both sounds are playing, the student hears a 'beat' with a frequency of 2Hz. What would the unknown frequency be

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.