Question

Cathode rays are passing through a discharge tube. In the tube, there is
(a) an electric field but no magnetic field
(b) a magnetic field but no electric field
(c) an electric as well as a magnetic field
(d) neither an electric nor a magnetic field

Answer 1

(c) an electric as well as a magnetic field

Cathode rays consist of beams of electrons that constitute current and, hence, magnetic field. We know electric field is produced by a charge, whether it is stationary or moving, So, electric field will also be present inside the tube.