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Worksheets5.1 Electron
Total questions: 16
Worksheet time: 9mins
“The emission of free electrons from a heated metal surface.” The following is the definition of
Thermionic emission
Ionic emission
Cathode ray
Maltese ray
Why must the glass tube be in a vacuum state?
To avoid a reaction to happen inside the glass tube
To ensure the electrons wouldn’t collide with air molecules
To reduce the pressure inside of the glass tube
To ensure the electron emission is controlled
_______ is a high velocity electron beam.
Ionic emission
Thermionic emission
Maltese ray
Cathode ray
What would happen if the connection to the E.H.T power supply is reversed?
The cathode ray’s velocity will be increased
Cathode ray will be polarized
The milliammeter will not show any readings
The milliammeter’s needle will deflect
What are the traits of a cathode ray?
Travels in a straight line
Positively charged
Negatively charged
Has mass
Possesses momentum and kinetic energy
There is an electron beam that accelerated from the cathode to the anode in a vacuum. The potential difference across the cathode and the anode is 600 V. What is the electrical potential energy of an electron?
[Mass of an electron, m = 9.11 × 10–31 kg, charge of an electron, e = 1.6 × 10–19 C]
5.47x1028 J
9.60x1017 J
5.47x10-28 J
9.60x10-17 J
In a cathode ray tube, the potential difference between the accelerating anode and the cathode in a vacuum is 200 kV. What is the kinetic energy of an electron when it reaches the anode?
[Mass of an electron, m = 9.11 × 10–31 kg, charge of an electron, e = 1.6 × 10–19 C]
3.20x10-14 J
1.82x10-25 J
3.20x1014 J
1.82x1025 J
In a cathode ray tube, the potential difference between the accelerating anode and the cathode in a vacuum is 1,112 V. What is the velocity of the electron before it hits the anode?
[Given charge of one electron, e = 1.60 × 10-19 C, electron mass, m = 9.11 × 10-31 kg]
1.98x107 ms-1
1.13x10-4 ms-1
3.91x1014 ms-1
6.33x10-9 ms-1
When an electron beam moves from the cathode to the anode in a vacuum tube, state the type of motion of the electron beam.
Travels upwards
Travels in a straight line
Travels downwards
Deflects to the right
Deflects to the left
When an electron beam moves from the cathode to the anode in a vacuum tube, state the transformation of energy.
Chemical > Heat > Light
Chemical > Heat > Kinetic
Heat > Kinetic > Light
Heat > Light > Kinetic
When an electron beam moves from the cathode to the anode in a vacuum tube, state the relationship between the voltage of E.H.T. power supply, V and the velocity of the electron, v.
V∝v2
V∝v
V∝v1
V∝v21
What rule is used to determine the direction of deflection of the cathode ray in magnetic field as in the diagram?
Fleming' left hand rule
Fleming' right hand rule
right hand grip rule
in cathode ray tube, the fluorescent screen glowing when cathode ray hit it. This implies that cathode ray:
moves in straight line
negatively charge
has momentum and kinetics energy
highly velocity
What is the primary purpose of the cathode in a cathode ray tube?
To emit electrons
To accelerate electrons
To collect electrons
To deflect electrons
In a vacuum tube, what happens to the kinetic energy of an electron as it moves from the cathode to the anode?
It decreases
It fluctuates
It increases
It remains constant
What type of radiation is produced when cathode rays strike a phosphorescent material?
Beta radiation
Visible light
Alpha radiation
Gamma radiation
