To reduce de-Broglie wavelength of an electron from `10^(-10)` m to`0.5xx10^(-10)` m,its energy should be …

Options

A. increased to 4 times
B. doubled
C. halved
D. decreased to fourth part

Answer

A

Explanation

`lambda=(h)/(sqrt(2mK))`
`therefore K prop (1)/(lambda^(2))`
`therefore (K_(2))/(K_(1))=((lambda_(1))/(lambda_(2)))^(2)=((10^(-10))/(0.5xx10^(-10)))^(2)=4`
`therefore K_(2)=4K_(1)`