The electric current in an X-ray tube (from the target to the filament) operating at `40 kV `is `10 mA`. Assume that on an average, 1% of the total kinetic energy of the electrons hitting the target are converted into X-rays and (b) how much heat is produced in the target every second?

Explanation

Given `V=30KV, i=10mA`
` 1%of T_(KE) (Total Kinetic Energy)`
` =X ray `
` i=ne `
` or n=10^-2/(1.6xx10^-19) `
` =0.625xx10^17 `
(number of electrons)
` KE of one electron =eV `
` =1.6xx10^-19xx40xx10^3 `
` =6.4xx10^-15J `
`T_(KE)=0.625xx6.4xx10^17xx10^-15`
` 4xx10^2J `
(a) power emitted in x-ray
` 4xx10^2xx1/100=4W `
Heat produced in target per second
` =400-4=396J `