What physical sign did you observer when you plucked each rubber band? did you hear any sound? what produce the sound?

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

What is the role of lenses in microscopy?

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b. b. at twice the distance, the magnitude of the field is 2b. c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.