A potential difference of `42,000 "volts"` is used in an `X` - ray tube to accelerate electrons . The maximum frequency of the `X` - radiations produced is

Options

A. `10^18 Hz`
B. `10^16 Hz`
C. `10^20 Hz`
D. `10^19 Hz`

Answer

D

Explanation

For continuous X rays , eV = `hv_(max)`
`therefore v_(max) = (eV)/(h) = (1.6xx10^(-19)xx4200)/( 6.63xx10^(-34))`
`= (6.72)/(6.63) xx10^19 = 10^19 Hz`
OR
`[lamda = (hc)/(ev) = c/v therefore v = (ev)/(h)]`