1. Which one of the following statements is correct concerning resonance in a system that can oscillate?
a. Resonance occurs when the frequency ofthe driving force is equal to the natural frequency of thesystem.
b. Resonance only occurswhen the driving force is equal to the weight of the oscillatingobject.
c. If the frequency of the driving force doesnot equal the natural frequency of the system,then the system does not oscillate at all.
2. Which one of the following statements is correct concerning theintensity, I, of a wave?
a. The intensity is a measure of theaverage energy per unit area perpendicular to thedirection of propagation of the wave.
b. The intensity is a measure of the averagepower per unit area perpendicular to the direction ofpropagation of the wave.
c. The intensity is ameasure of the average force per unit area perpendicularto the direction of propagation of the wave.
3. Suppose that the intensity at a distance r from anisotropic wave source is I. Neglect any energy loss to themedium. The intensity at a distance of 2r from the sourceis...
a.¼I
b.½I
c.2I
d. 4I