Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectric Current through Gases

Cathode rays are travelling through a discharge tube. Inside the tube, there exists

Options

Aa magnetic field but no electric field
Bneither an electric nor a magnetic field
Can electric field as well as a magnetic field
Dan electric field but no magnetic field

Correct answer

C. an electric field as well as a magnetic field

Step-by-step solution

Cathode rays are produced and accelerated by applying a high potential difference between the cathode and the anode. This applied potential difference establishes an electric field inside the discharge tube. Cathode rays consist of a stream of moving electrons. Since moving charges constitute an electric current, they produce a magnetic field in the surrounding space inside the tube. Therefore, both an electric field and a magnetic field exist inside the discharge tube.

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