Q1. A person wears a hearing aid that uniformly increases the intensity level of all audible frequencies of sound by 29.7 dB. The hearing aid picks up sound having a frequency of 250 Hz at an intensity of 3.10 10-11 W/m2. What is intensity delivered to the eardrum?
Q2. A converging lens (f = 10.0 cm) is held 8.60 cm in front of a newspaper, the print size of which has a height of 1.86 mm. Determine (a) the image distance (in cm) and (b) the height (in mm) of the magnified print?
Q3. A ray of light is incident at an angle of 48.8 degrees on the surface of a piece of crown glass whose index of refraction is 1.52.
What is an angle of refraction?