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If we want to observe inside atom.Assume...

If we want to observe inside atom.Assume diameter of atom 100 pm That means we can determine region of about 10 pm.For this electron microscope is used. Minimum required energy of electron should be ……

A

1.5 keV

B

15 keV

C

150 keV

D

1.5 MeV

Text Solution

Verified by Experts

The correct Answer is:
B
In electron microscope,electron is used as source of energy.
Resolving power of microscope is about wavelength of light used .de-Broglie wavelength of particle with mass m and velocity v will be ,
`lambda=(h)/(p)=(h)/(mv)`
Required speed of electron,
`v=(h)/(mlambda)=(6.63xx10^(-34))/(9.11xx10^(-11))`
`=7.28xx10^(7) (m)/(s)` corresponding kinetic energy,
`E=(1)/(2)mv^(2)`
`(1)/(2)xx9.11xx10^(31)xx(7.28xx10^(7))^(2)xx(1eV)/(1.6xx10^(-19)J)`
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