What is the minimum voltage to be applied toan X ray bulb to obtain all the lines of K series with anticathode made of copper? 1) 5,700V 2) 10,700V 3)15,700V 4)20,700V

Voltage supply gives the energy to electron=

Energy required to knock out the K shell electron form Copper atom is equal to the minimum voltage required to get all the charesteristic peaks of Copper

Now for the necessary event to take place,


From quating the two equations:

Substituting the values of constants,
we get ,

almost equal to 10,700 V