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If the kinetic energy of an electron is made four times larger, how will the wavelength of its associated de Broglie wave change?
- become one-fourth
- become half
- become four times
- become twice
Correct answer: become half
Solution
The de Broglie wavelength is inversely proportional to the square root of the kinetic energy. Therefore, if the kinetic energy is increased four times, the wavelength will decrease by a factor of the square root of four, which is two, resulting in the wavelength becoming half.
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