Q70 / 91 · KVPY 2020 (SB/SX) · Physics
A collimated beam of charged and uncharged particles is directed towards a hole marked on a screen as shown below. If the electric and magnetic fields as indicated below are turned on

A collimated beam of charged and uncharged particles is directed towards a hole marked on a screen as shown below. If the electric and magnetic fields as indicated below are turned on

- Aonly particles with speed will go through the hole
- Bonly charged particles with speed and neutral particles will go through
- Correct answerConly neutral particles will go through
- Donly positively charged particles with speed and neutral particles will go through
Solution
For charged particles

net force is in downward direction, so they won't be able to go through the hole
And uncharged particle don't deviate so they will be able to go through hole
Hence, the correct answer is option: 'C'.