The angle between the incident ray and the normal is called __________

(angle of incidence, angle of reflection, angle of refraction)

Reflection from a smooth surface is called _____________reflection.

(regular, irregular, multiple, total internal)

If the angle of incidence is 40° the angle of reflection is __________

(10°, 40°, 20°, 90°)

Fill in the blanks:

1. The working principle of a periscope is __________________

2. A fruit appears to be bigger in a glass of water due to _____________

3. Sound cannot travel in ___________

4. When we touch the ringing bell we can feel the ______________

5. An audible sound has the frequency range of _____________

Identify the mistakes and correct them:

The beautiful pattern that we obtain in a kaleidoscope is because of refraction.