AAMC C/P Section Bank #4

[Dr. To Be]

Hey all.

Can someone explain whey the answer is D? I know from E=hf=hc/wavelength that f and wavelength are inversely proportional to one another. So if f is increasing by 2, wavelength will decrease by 2. I guess I'm confused as to why the answer is 532 nm and not 133nm (266/2). Thanks!

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[MedicalMermaid]

So the way I had looked at this question was by only looking at the options first before putting it in context of the passage. The question asks which of the lasers (A, B, C or D) would be suitable for the technique in the passage if the frequency of this laser was doubled. It is asking about the option choices only, not the lasers mentioned in the passage.

Like you said, frequency and wavelength are inversely proportional. Therefore, we know if frequency is doubled, then wavelength must be halved. Apply this to the options. For example, in option A, if this laser's frequency is doubled, then the wavelength must be 826/2 = 413nm. This can't be correct as the passage states that only wavelengths 266 and 325 are used for MALDI. If you evaluate each option only looking at wavelength, you should find that options C and D are both possibilities as the wavelengths match with the ones given in the passage.

The reason D is correct is because both the wavelength (after you divide it by 2) and power match up to the one given in the passage (266 nm at 1.5 mW). Option C is wrong because the power is too low. For C to be correct, the power would have had to been 2.2 mW instead of 1.5.

Hope that helps 🙂

 

[Dr. To Be]

So the way I had looked at this question was by only looking at the options first before putting it in context of the passage. The question asks which of the lasers (A, B, C or D) would be suitable for the technique in the passage if the frequency of this laser was doubled. It is asking about the option choices only, not the lasers mentioned in the passage.

Like you said, frequency and wavelength are inversely proportional. Therefore, we know if frequency is doubled, then wavelength must be halved. Apply this to the options. For example, in option A, if this laser's frequency is doubled, then the wavelength must be 826/2 = 413nm. This can't be correct as the passage states that only wavelengths 266 and 325 are used for MALDI. If you evaluate each option only looking at wavelength, you should find that options C and D are both possibilities as the wavelengths match with the ones given in the passage.

The reason D is correct is because both the wavelength (after you divide it by 2) and power match up to the one given in the passage (266 nm at 1.5 mW). Option C is wrong because the power is too low. For C to be correct, the power would have had to been 2.2 mW instead of 1.5.

Hope that helps 🙂

OMG! Thanks so much! I get it now!