The diagram above illustrates a cathode ray tube.... | WAEC SSCE - Physics - 2016

Question 1 Report

The diagram above illustrates a cathode ray tube. Identify the components X, Y, and Z.

Answer

Identifying the components of the cathode ray tube. Following the electron beam from left (the electron gun) to right (the screen end):

X - the filament/cathode (heater of the electron gun). X is connected to the coil at the far left. When heated by the low-voltage supply it emits electrons by thermionic emission, providing the source of electrons for the beam.
Y - the anode (accelerating and focusing anodes). Y points to the cylindrical electrodes held at a high positive potential. They accelerate the electrons and focus them into a fine beam directed along the axis of the tube.
Z - the deflecting plates. Z points to the pair of parallel plates. A potential difference applied across them sets up an electric field that deflects the electron beam, steering the spot on the fluorescent screen.

In summary: X = cathode/filament (electron source), Y = accelerating anode, Z = deflecting plates.

Answer Details

Identifying the components of the cathode ray tube. Following the electron beam from left (the electron gun) to right (the screen end):

X - the filament/cathode (heater of the electron gun). X is connected to the coil at the far left. When heated by the low-voltage supply it emits electrons by thermionic emission, providing the source of electrons for the beam.
Y - the anode (accelerating and focusing anodes). Y points to the cylindrical electrodes held at a high positive potential. They accelerate the electrons and focus them into a fine beam directed along the axis of the tube.
Z - the deflecting plates. Z points to the pair of parallel plates. A potential difference applied across them sets up an electric field that deflects the electron beam, steering the spot on the fluorescent screen.

In summary: X = cathode/filament (electron source), Y = accelerating anode, Z = deflecting plates.

The diagram above illustrates a cathode ray tube. Identify the components X, Y, and Z.