Read the introduction to a personal statement. usually, when people talk about "rocky” relationships, it’s with a frown, but mine has enriched my life. i became fascinated with rocks when i was really young, and throughout my childhood you could usually find me with my pockets bulging from whatever stony treasures i’d scavenged that day. when my science teacher taught us a unit on geology, i realized that my fascination could become an exciting career that could also me make good money. obtaining an internship to work on the geological exhibit at the museum is an important step on my road to being a geologist.

the topic of the personal statement can best be described as the

reason rocks are interesting.
pursuit of a career in geology.
importance of learning geology.
impact of a good science education.

The correct answer is B. Pursuit of a career in geology

Explanation:

A personal statement is a text you write as part of your application to a university or college, in this text you provide information about your experiences, and motivations for a certain career. In the case of the introduction presented, the author focuses on narrating the events that took him to select geology as a career, this mainly based on experiences during childhood "I became fascinated with rocks when I was really young", "my science teacher taught us a unit on geology, I realized that my fascination could become an exciting career". This means this text focuses on the way, the author discovered his vocation and at the same time, the way the author pursued this path through past experiences or the pursuit of a career in geology.

sound is invisible, but sometimes we can feel it. when a kettle-drum is thumped with a stick that time the tight drum skin moving up and down very quickly for some time and then it pumped sound waves into the air. loudspeakers also work in a similar manner.

components of a speaker:

electromagnet

in order to translate an electrical signal into an audible sound, an electromagnet is used in looudspeakers

  suspension

suspension is used to   center the voice coil in the gap of the magnet and it exerts a restoring force to keep it there. suspension is used to limits the maximum mechanical excursion of the diaphragm and voice coil.

voice coil

voice coil is a coil of wire which is attached to the apex of a loudspeaker cone. it provides the motive force to the cone by the reaction of a magnetic field to the current passing through it.

cone

in a   loudspeaker, a   thin, semi-rigid membrane attached to the voice coil, which moves in a magnetic gap due to which it vibrates   and produced sound. it is known as diaphragm and it can also be called a cone, though not all speaker diaphragms are cone-shaped.

surround

surround is also known as front suspension. surround is used to join the cone to the chassis. together with the suspension it controls the cone excursion, and it is also used to   determine how energy which is   travelling through the cone is absorbed, and how the speaker limits when it reaches the ends of its travel.

dustcap

dustcap is used to protect the voice coil from dust and dirt. it is a part of the cone.

how speaker work

the outer part of the cone is fastened to the outer part of the loudspeaker's circular metal rim. the inner part is fixed to   voice coil that sits just in front of a permanent magnet . when loudspeaker is hooked up to a stereo, electrical signals feed through the speaker cables into the coil. it will convert the coil into an electromagnet magnet . when electricity flows back and forth in the cables, the electromagnet either repels or attract the permanent magnet. this moves the coil back and forth, and it pull and push the loudspeaker cone. like a drum skin vibrating back and forth, the moving cone pumps sounds out into the air.in this way loudspeakers works.