3. Figure shows circular region of radius \( R =\sqrt{3} m \) in which upper half has uniform magnetic field i tried my best but charges each having mass \( m =2 gm \), speed \( v =0.3 m / sec \) and charge \( q =+1 mC \) are projected along the diameter as shown in figure. A screen is placed perpendicular to initial velocity of charges as shown. If the distance between the points on screen where charges will strikes after being deflected by the magnetic field is \( 4 X \) meters, then calcuiate \( X \).
