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### 1A.3 7th Edition Question

Posted: Sun Oct 14, 2018 8:19 pm
1A.3 Which of the following happens when the frequency of electromagnetic radiation decreases? Explain your reasoning.
(c) The extent of the change in the electrical field at a given point decreases. Can someone explain what happens to the "extent of the change in the electrical field at a given point" when the frequency of electromagnetic radiation decreases? Thanks.

### Re: 1A.3 7th Edition Question

Posted: Sun Oct 14, 2018 8:25 pm
As the frequency decreases, the waves broaden (wavelength increases). The extent of the change is the slope of the wave; therefore, the extent of the change also decreases.

### Re: 1A.3 7th Edition Question

Posted: Sun Oct 14, 2018 11:22 pm
Exactly. Frequency and wavelength have an inverse relationship so as one increases, the other decreases. In this case, decreasing frequency means increasing wavelength. If you were to visualize this, it would mean the waves are getting elongated (less steep). Therefore, the slope decreases as well.

### Re: 1A.3 7th Edition Question

Posted: Mon Oct 15, 2018 4:16 pm
It's a fancy way of saying wavelength increases, and we know that because c = wavelength x frequency

### Re: 1A.3 7th Edition Question

Posted: Tue Oct 16, 2018 12:44 pm
I agree with all the comments above. The extent of the change in the electrical field and amplitude correspond with each other. When frequency decreases, the slope of the wave decreases because of the change in amplitude. Therefore, the extent of change also decreases as the frequency of the electromagnetic radiation decreases.