The charge on a small point object at $$A$$ produces an electric potential $$V=3\ \text{V}$$ at a point $$P$$. Because of an unavoidable situation, leakage of the charge from the object at $$A$$ starts at $$t=0$$ at a constant rate of $$3\ \mu\text{C s}^{-1}$$. To maintain the potential of $$3\ \text{V}$$ at the point $$P$$, the object is made to move towards $$P$$ with a certain velocity $$v$$. When the point object crosses the point $$D$$ shown in the figure, it is found to have a charge of $$10\ \mu\text{C}$$ and the direction of its velocity is perpendicular to $$OD$$. The resulting magnetic field $$B$$ at this instant at the location $$O$$, such that $$OD=1.0\ \text{m}$$, is