Dr. Anatoly Miroshnichenko

Extra Credit Conceptual Questions
 

In order to test your understanding of observed phenomena and basic concepts learned in the course, you can answer conceptual questions given below and get up to 10% (one letter grade) of extra credit to your final grade. Some of the questions might have been used in homework.

How does it work?

You pick up to 10 conceptual questions from the list below, find answers to them (in the course book, other books, the internet, etc.), and submit detailed answers via email (anatoly@physics.utoledo.edu) by April 25th. Use any text editor, including MS Word. Type in the question, concept(s) or formula you used to approach it (skip this if you do not see which concept or formula is applicable), and a detailed answer (a few sentences). Each correctly and fully answered question will bring you 1% extra credit to your final grade for the course (maximum 10%). One line answers will not be accepted. For examples of how to answer the questions see the course book (all odd numbered conceptual questions in each chapter have answers on pages A17 - A31 (at the end of the book) and an example below.

More conceptual questions can be added later.

Example of answering a conceptual question.

Question: Why does the arc of a rainbow appear with red on top and violet on the bottom?

Answer: Dispersion of light is the key concept to answer this question. Sunlight consists of photons of different wavelengths, which are refracted at different angles at the front surface of raindrops. The violet light (the lowest wavelength seen by eye) is deviated the most from the direction of incidence, the red light (the greatest wavelength) is deviated the least. The light is then reflected at the drop's back surface and refracted one more time at the front surface, when leaving the drop. As a result, the angle between the directions of incidence of the white light and the direction of returning of the violet light is 40^o. The same angle is 42^o for the red light. The red light from a raindrop, high in the sky, can reach the observer because it is deviated the most from the direction of incidence. This drop is seen as red. The violet light from the same drop passes over the observer, because it is deviated the least. In order to be seen as violet, a raindrop should be located lower in the sky. Thus, a rainbow is red on top and violet on the bottom.

Conceptual Questions for Extra Credit

Use the atomic theory of matter to explain why the resistance of a material should increase as its temperature increases.

Are the two headlights of a car wired in series or in parallel? Explain.

How can a current loop be used to determine the presence of a magnetic field in a given region of space?

Can a constant magnetic field set into motion an electron at rest? Explain.

Do all current-carrying conductors emit electromagnetic waves? Explain.

How is it possible that a complete circle of a rainbow can sometimes be seen from an airplane?

Light of only two colors (X and Y) is sent through a glass prism. The light of color X is bent more than the light of color Y. Which color travels more slowly in the prism?

Explain the phenomenon called looming, a type of mirage formed when if the air gets gradually warmer as the height increases.

Why are lenses in eyeglasses are always designed so that the middle of the lens curves away from the eye?

Why is it difficult to focus a telescope on an object very close to you?

Explain why a dielectric increases the maximum operating voltage of a capacitor although the physical size of the capacitor does not change.

What two speed measurements will two observers in relative motion always agree on?

Why is an electron microscope more suitable than an optical microscope to view objects of an atomic size?

List some ways in which quantum mechanics altered our view of the atom pictured by the Bohr theory.

Why is it not a good idea to seek shelter under a tree during a lightning storm?

Explain why beta particles can expose a film, placed in a box, while alpha particles cannot.

If the cosmic ray intensity was much greater 10000 years ago, how would this affect the ages we assign to ancient samples of once-living matter?

Why is it difficult to focus a microscope on an very distant object?

Why would a fusion reactor produce a less radioactive waste than a fission reactor?