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Question
What happens when an electron collides with a positron?
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Solution
They annihilate each other, producing gamma ray photons.
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What do you understand by the statement, "Electromagnetic waves transport momentum"?
If the potential difference applied to the tube is doubled and the separation between the filament and the target is also doubled, the cutoff wavelength
For harder X-rays,
(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
The Kβ X-ray of argon has a wavelength of 0.36 nm. The minimum energy needed to ionize an argon atom is 16 eV. Find the energy needed to knock out an electron from the K shell of an argon atom.
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| Gamma rays | D | C | Visible light | B | A |
The above table shows different parts of the electromagnetic spectrum.
(a) Identify the parts of the spectrum marked as A, B, C and D.
(b) Which of the radiations A or B has the higher frequency?
(c) State two properties which are common to all parts of the electromagnetic spectrum.
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(e) Name one detector for each of the radiation.
(f) Name one use of each of the radiation.
Name any two electromagnetic waves which have a frequency higher than that of violet light. State one use of each.
State three properties of ultra-violet radiation similar to visible light.
Answer briefly.
What are radio waves?
