Question

The two lines A and B in fig. show the photo electron of de Broglie wavelength `(lamda)` as a function of `(1)/(sqrtV) `(V is the accelerating potential) for two particles having the same charge. Which of the two represents the particle of heavier mass?

Answer 1

`:. lambda=(h)/(sqrt(2meV))rArrlambda=(h)/(sqrt(m.)sqrt(2e)).(1)/(sqrt(V))`
`because` Slope of `B gt` Slope of `A`
`(1)/(sqrt(m_(B))) gt (1)/(sqrt(m_(A)))rArr sqrt(m_(B)) lt sqrt(m_(A))`
`:. m_(B) lt m_(A)`
Therefore, line `B` represents a particle of smaller mass.