In electron microscope 25 kV voltage is used to accelerate electron .By changing voltage to 100 kV de-Broglie wavelength becomes..

Options

A. increases by two times
B. decrease by two times
C. decreases by four times
D. increase by 4 times

Answer

B

Explanation

`lambda prop (1)/(sqrt(V))`
`implies(lambda_(1))/(lambda_(2))=sqrt((V_(2))/(V_(1)))=sqrt((100kV)/(25kV))=2`
`implieslambda_(2)=(lambda_(1))/(2)`