Question

An infinitely long wire carrying a current I in vertically upward direction (y-direction) is placed near the surface of earth as shown in figure. Neglect the earth's magnetic field :

At some time t a particle is at point A(a, 0) and moving towards origin with velocity V. If the acceleration of particle at point A is 2g in downward direction then :

(A) particle is negatively charged

(B) particle is positively charged

(C) magnitude of charge on the particle is (πamg/μ₀VI)

(D)  magnitude of charge on the particle is  (2πamg/μ₀VI)

Answer 1

Correct option  (B)(D)

Explanation:

B = μ₀I/2πa  by the direction of force particle is positively charge.

Now