# An electron having an energy of 20 eV enters a magnetic field of 0.02 webers/sqm at an angle of 30degrees...

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An electron having an energy of 20 eV enters a magnetic field of 0.02 webers/sqm at an angle of 30degrees to the field. The time of travel (in nS)of the electron for one revolution is about

A) 1.78 B) 4.21 C) 7.82 D) 10.24

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