An electron (mass 9×10^-31 kg and charge 1.6×10^-19C) moving with speed c/100 (c = speed of light) is injected into a magnetic field B of magnitude 9×10^-4 T perpendicular to its direction of motion. We wish to apply an uniform electric field E toget…

An electron (mass \(9\times10^{-31}\) kg and charge \(1.6\times10^{-19}\)C) moving with speed \(c/100\) (\(c\) = speed of light) is injected into a magnetic field \(\vec B\) of magnitude \(9\times10^{-4}\) T perpendicular to its direction of motion. We wish to apply an uniform electric field \(\vec E\) together with the magnetic field so that the electron does not deflect from its path. Then (speed of light \(c = 3\times10^{8}\) ms\(^{-1}\))

1. \(\vec E\) is perpendicular to \(\vec B\) and its magnitude is \(27\times10^{4}\) V m\(^{-1}\)

2. \(\vec E\) is perpendicular to \(\vec B\) and its magnitude is \(27\times10^{2}\) V m\(^{-1}\)

3. \(\vec E\) is parallel to \(\vec B\) and its magnitude is \(27\times10^{2}\) V m\(^{-1}\)

4. \(\vec E\) is parallel to \(\vec B\) and its magnitude is \(27\times10^{4}\) V m\(^{-1}\)