JEE Main levelSingle correct optionDifficulty 2 of 3as124
A proton and an α-particle (mass 4 times that of a proton, charge 2e) are accelerated from rest through the same potential difference. The ratio λp/λα is
A0.5
B4
C2.828
D2
Answer: C
λ=h/2mqV, so λ∝1/mq. Then λp/λα=(4×2)/(1×1)=8=2.828.