Posted by Mary on Monday, November 5, 2007 at 8:21pm.

Suppose that the electric field of an electromagnetic wave decreases in magnitude. Does the magnetic field increase, decrease, or remain the same?

Account for your answer.


For Further Reading

Physics - bobpursley, Monday, November 5, 2007 at 9:07pm
I will be happy to critique your thinking. It is not nice to post a lot of questions with each a different name. Usually, slackers or answer moochers do that.



Physics - Mary, Monday, November 5, 2007 at 9:34pm
As I said in the previous post, you are mistaking me for someone else. Maybe there is someone in my class who is also using this website. You and drwls have been helping me with my physics homework since the spring semester and I know better not to pretend to be someone else. I will make an educated guess and repost this question.

My educated guess:

It will decrease. The formula E=cB shows the relationship between the magnitudes of the electric and magnetic field in an electromagnetic wave. The value of c is constant and E is is proportional to B. If you decrease the value of the electric field the value of the magnetic field will also decrease and vise versa.

Answer is correct.

Your educated guess is correct. The relationship between the electric field (E) and the magnetic field (B) in an electromagnetic wave is given by the equation E=cB, where c is a constant. This equation shows that the magnitudes of the electric and magnetic fields are proportional to each other.

Since the formula states that E=cB, if the electric field decreases in magnitude, it implies that the value of E decreases. According to the formula, this means that the value of B (the magnetic field) will also decrease, since they are proportional to each other.

In summary, when the electric field of an electromagnetic wave decreases in magnitude, the magnetic field decreases as well.