X-ray tubes and cathode ray tubes are practical applications of thermionic emission - Leaving Cert Physics - Question 10 - 2016
Question 10
X-ray tubes and cathode ray tubes are practical applications of thermionic emission. Thermionic emission causes the emission of electrons, which are sub-atomic parti... show full transcript
Worked Solution & Example Answer:X-ray tubes and cathode ray tubes are practical applications of thermionic emission - Leaving Cert Physics - Question 10 - 2016
Step 1
State two properties of the electron. Name another sub-atomic particle.
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Answer
The properties of the electron are:
It has a negative charge.
It has a very small mass compared to protons and neutrons.
Another sub-atomic particle is the proton.
Step 2
Name the parts labelled A, B, and C in the diagram.
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A: Cathode
B: Anode
C: Screen
Step 3
State the function of any two of these parts.
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The cathode emits electrons when heated (thermionic emission).
The anode attracts the emitted electrons, allowing them to move towards the screen.
Step 4
How could the beam of electrons be deflected?
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The beam of electrons can be deflected by using magnetic fields or electric fields. An external magnetic field can bend the path of the electrons due to the Lorentz force.
Step 5
Why is it important to have a vacuum inside a cathode ray tube?
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A vacuum is essential to prevent the electrons from colliding with air molecules, which would scatter them and reduce the effectiveness of the electron beam.
Step 6
State one use of a cathode ray tube.
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One use of a cathode ray tube is in the display screens of older televisions and computer monitors.
Step 7
Draw a sketch of an X-ray tube.
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A basic sketch should include:
Anode
Cathode
Target
Filament
Cooling fins
Step 8
Why are lead aprons often worn when using an X-ray tube?
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Lead aprons are worn to protect the body from unnecessary exposure to ionizing radiation, which can have harmful effects.
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