An infinite line charge of charge density λ has a charged particle (–q, m) revolving about it in a circle of radius r. Find he orbital speed.
(1) \(\sqrt{\frac{λa}{\piε_0m}}\)
(2) \(\sqrt{\frac{λq}{4\piε_0m}}\)
(3) \(\sqrt{\frac{4λa}{\piε_0m}}\)
(4) \(\sqrt{\frac{λa}{2\piε_0m}}\)