JEE MainPhysicsMagnetic Effects of Current
A particle of mass m and charge q is projected into a region containing a uniform magnetic field described by B = B₀ i . If the initial velocity of the particle is v = v₀ i + v₀ j , what is the magnitude of its initial acceleration?
Options
- A2 q v₀ B₀ m
- Bq v₀ B₀ m
- C0
- D2 q v₀ B₀ m
Correct answer
B. q v₀ B₀ m
Step-by-step solution
The magnetic force on a moving charge is given by F = q( v B ) . Substituting the given vectors: F = q((v₀ i + v₀ j ) B₀ i ) Using the properties of cross products, i i = 0 and j i = - k . F = q(v₀ B₀ ( i i ) + v₀ B₀ ( j i )) = -q v₀ B₀ k The magnitude of the magnetic force is | F | = q v₀ B₀ . The magnitude of the initial acceleration is a = | F | m = q v₀ B₀ m . Answer: q v₀ B₀ m