Question

A particle of positive charge q and mass m enters with velocity vj at the origin in a magnetic field B () which is present in the whole space. The charge makes a perfectly inelastic collision with identical particle at rest but free to move at its maximum Y-coordinate. After collision the combined charge will move on trajectory (where r = ) –

• A. y = $\frac { \mathrm { mv } } { \mathrm { qB } }$ ( $- \hat { \mathbf { i } }$ )
• B. (X + r)² + (Y – r/2)² = r²/4
• C. (X – r)² + (Y – r)² = r²
• D. (X – r)² + (Y + r/2)² = r²/4

Answer 1

Answer: (B)

(X + r)² + (Y – r/2)² = r²/4

Answer 2

The charged particle moves I a circle of radius $\frac { \mathrm { a } } { 2 }$ qvB = $\frac { \mathrm { mv } ^ { 2 } } { \mathrm { a } / 2 }$

or B =