Question

An electron is accelerated through a potential v, its de broglie wavelength is lambda. if accelerating voltage is increased to 4v, its de broglie wavelength will become
A)4 lambda
B)2 lambda
C)lambda
D)lambda/2​

Answer 1

lambda inversly proportional to square root of v. if v increases to 4v means ,square root of 4 becomes 2...so answer will be 2 lambda