m=0.6g=0.6×10−3‌kg,q=25‌nC=25×10−9C v=1.2×104m∕s The particle is moving with uniform velocity (acceleration is zero), so magnetic force will be balancing the weight of the particle. mg‌=Bqv 0.6×10−3×10‌=B×25×10−9×1.2×104 B‌=‌
