Statement -I : If the potential difference applied to an electron is made 4 times, the de-Broglie wavelenght
assoiated is halved. (Initial kinetic energy of the electron was zero ).
Statement -II : On making potential difference 4 times velocity is doubled and hence according to
De -broglie hypothesis`lambda` is halved.

Options

A. If both Statement -I & Statement -II are True & the Statement -II is a correct explanation of the Statement
I.
B. If both Statement -I & Statement -II are True but the Statement -II is not a correct explanation of the
Statement- I.
C. If Statement -I is True but the Statement -II is False.
D. If Statement -I is True but the Statement -II is True .

Answer

A

Explanation

`lambda_(1)=sqrt((150)/(V))Å`, `lambda_(2)sqrt((150)/(4V))Å`=`(1)/(2)sqrt((150)/(V))Å`=`(lambda_(1))/(2)`
`(1)/(2)m_(e)u_(1)^(2)=eV" "(1)/(2)m_(e)u_(2)^(2)=4eV`
`rArru_(1)sqrt((2eV)/(m_(e)))" "rArru_(2)=2xxsqrt((2eV)/(m_(e)))`
`lambda_(1)=(h)/("mu"_(1))" "2mu_(1)`
`lambda_(2)=(h)/("mu"_(2))`=`(h)/("2mu"_(1))`=`lambda_(1)/(2)`