physics paper 1

Question 1

🃏 Flashcard 1
Q: What would the screen pattern look like if electrons behaved only as particles?
A: A small spot of light, or a random scatter — not a clear pattern. ✅

🃏 Flashcard 2
Q: What wave property is shown by the pattern on the screen from electrons passing through graphite?
A: Diffraction and interference ✅

🃏 Flashcard 3
Q: What does the graphite target cause the electron beam to do (wave behaviour)?
A: It causes the electron waves to spread out or travel in particular directions. ✅

🃏 Flashcard 4
Q: Why do bright rings appear on the screen in the electron diffraction experiment?
A: Constructive interference — the waves arrive in phase. ✅

🃏 Flashcard 5
Q: What equation is similar to the pattern formed by electron diffraction?
A:
sin
⁡
𝜃
=
𝑛
𝜆
𝑑
sinθ=
d
nλ
​
(like a diffraction grating). ✅

🃏 Flashcard 6
Q: How does light emission from a fluorescent screen show particle behaviour of electrons?
A: Energy is transferred in 1-to-1 collisions — not gradually like a wave. ✅

🃏 Flashcard 7
Q: What must electrons do to cause excitation in atoms on the fluorescent screen?
A: Provide enough kinetic energy instantly to excite an electron to a higher energy level. ✅

🃏 Flashcard 8
Q: What causes light to be emitted from the screen when struck by electrons? (Give 2 points)
A:

Excitation then de-excitation of electrons in the screen atoms ✅

Collisions raise electrons to higher levels; light is emitted when they fall back down ✅

🃏 Flashcard 9
Q: What is required for a stationary wave to form on a stretched string?
A: Reflection of waves at boundaries causing interference. ✅

🃏 Flashcard 10
Q: How do stationary waves form from two travelling waves?
A: They travel in opposite directions and interfere or superpose. ✅

🃏 Flashcard 11
Q: Why do fixed boundaries become nodes in a stationary wave?
A: The boundary can’t move, so the waves cancel completely there — destructive interference. ✅

🃏 Flashcard 12
Q: What are antinodes and how do they form?
A: Positions of maximum amplitude due to constructive interference. ✅

Question 2

what happens when a

Answer 2

at higher temperature more charge carries become available