Question

The magnetic field is perpendicularly into the plane of the paper and a few charged particles are projected in it. Which of the following statement is true?

• A. A represents proton and B and electron
• B. Both A and B represent protons but velocity of A is more than that of B
• C. Both A and B represents protons but velocity of B is more than that of A
• D. Both A and B represent electrons, but velocity of B is more than that of A

Answer 1

The correct option is C Both A and B represents protons but velocity of B is more than that of A

Both particles are deflecting in same direction so they must be of same sign.(i.e., both A and B represents protons)
By using $r=\frac{mv}{qB}\Rightarrow r\propto v$
From given figure radius of the path described by particle B is more than that of A.
Hence $v_B>v_A$.