JEE Advanced 2020 Concept Recapitulation Test 2 Paper 2

A proton is fired from very far away towards a nucleus with charge =120e, where e is the electronic charge. It makes a closest approach of 10fm to the nucleus. The de Broglie wavelength (in units of fm ) of the proton at its startis: (take the proton mass,
mp=(5∕3)×10−27kg;h∕e=4.2×10−15J.s∕C;‌

1

4πε0

=9×109m∕F;1fm=10−15m)