--- title: Mirrors, rainbows and the blue sky — how Mova does on the tests · Physics description: Lesson 21 of the physics course of Mova's primary school: 5 of 11 tests right, exam 1 of 4, every question with the options, the student's choice, the right answer and why it chose. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/school-run/physics/21-mirrors-rainbows-and-the-blue-sky/) [home](https://md.mova.elamur.ai/free/en/) / [at school](https://md.mova.elamur.ai/free/en/school-run/) / [Physics](https://md.mova.elamur.ai/free/en/school-run/physics/) / 21 # Mirrors, rainbows and the blue sky **Tests:** 5 of 11 right · **Exam:** 1 of 4 right · **Kind:** ★ · **Understood:** 9 of 15 · **Run:** 2026-10-18, commit `f3c23ea72` Lesson 21 of the physics course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: [the lesson in the corpora](https://md.mova.elamur.ai/free/en/corpora/school/physics/21-mirrors-rainbows-and-the-blue-sky/). Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/). ### Test 1 · ★ · wrong ✗ {#t1} Me cousin says the sky's blue cos it reflects the sea. Is that right? - **1.** Yes, and over deserts the sky is yellow — **← Mova's choice** · no support - **2.** No, the air scatters blue light more than other colours — **✓ the right answer** · no support - **3.** No, the sky is blue because the space behind the air is blue — no support - **4.** Yes, the sea paints the sky blue — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t1/) ### Test 2 · ★ · right ✓ {#t2} What colour is the daytime sky seen from the Moon? - **1.** White, like a cloud — no support - **2.** Blue, just like on Earth — no support - **3.** Red, like a sunset — no support - **4.** Black, because there is no air to scatter light — **← Mova's choice** · **✓ the right answer** · score 7 **Why:** It took the question to ask who or what does it. It chose option 4 with score 7, the only option with support. Its support: lesson 20, line 5: «Light things bounce most light away and dark things soak it up and turn it into warmth, and the colour you see is the light a thing bounces back to you.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+3); the same doer «colour» (+2); the same thing acted on «light» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t2/) ### Test 3 · ★ · wrong ✗ {#t3} After a big volcano erupts, sunsets around the world look extra red. Why? - **1.** The volcano heats up the Sun — no support - **2.** Glowing light from the hot lava reflects all over the sky — **← Mova's choice** · score 6 - **3.** Dust in the air scatters away even more of the blue — **✓ the right answer** · score 5 - **4.** The volcano paints the clouds red — no support **Why:** It took the question to ask why something happens (its cause). It chose option 2 with score 6, against 5 for the next best. Its support: lesson 20, line 15: «A red apple looks red because it bounces red light and soaks up the other colours; under a blue lamp it looks almost black.», reached through the cause of the sentence the question matched. What matched: the same thing acted on «red light» (+5); a different action (counts against) (+1). The right option, 3, scored 5. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t3/) ### Test 4 · ★ · right ✓ {#t4} In a cartoon a leprechaun hides gold where the rainbow touches the ground. Why could you never get there? - **1.** It is always in another country — no support - **2.** The leprechaun moves it to a new place every night — no support - **3.** The rainbow moves as you move and has no fixed end — **← Mova's choice** · **✓ the right answer** · score 4 - **4.** The gold is invisible in daylight — no support **Why:** It took the question to ask why something happens (its cause). It chose option 3 with score 4, the only option with support. Its support: lesson 21, line 3: «You only ever see a rainbow with the Sun behind you, and it has no end you can walk to, so there is no pot of gold.», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «end» (+2); the same doer «rainbow» (+1); the same light verb (be, have, do, get, go) (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t4/) ### Test 5 · ★ · wrong ✗ {#t5} Why does a heron stab a little beside where the fish appears to be? - **1.** Light bending at the surface makes the fish look shifted — **✓ the right answer** · score 2 - **2.** Herons have bad eyesight — no support - **3.** Fish swim backwards to trick herons — **← Mova's choice** · score 6 - **4.** The heron's beak is bent — no support **Why:** It took the question to ask why something happens (its cause). It chose option 3 with score 6, against 2 for the next best. Its support: lesson 13, line 17: «A goldfish stays at one depth by keeping just the right amount of gas in its swim bladder, and a fish floating on its side may have a sick swim bladder.», reached through the same lesson line as the sentence the question matched. What matched: the same action «float» (+4); the same doer «fish» (+2). The right option, 1, scored 2. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t5/) ### Test 6 · ★ · right ✓ {#t6} Why do rain clouds look dark grey? - **1.** They are full of black dust — no support - **2.** They are colder than white clouds — no support - **3.** They are reflecting the dark ground and the sea under them — no support - **4.** They are so thick that hardly any light gets through — **← Mova's choice** · **✓ the right answer** · score 9 **Why:** It took the question to ask why something happens (its cause). It chose option 4 with score 9, the only option with support. Its support: lesson 21, line 16: «Clouds are white because their droplets are much bigger than air molecules and scatter all colours equally; thick rain clouds look grey because little light ge…», reached through the cause of the sentence the question matched. What matched: the same property (+4); the same action «get through» (+3); the same doer «little light» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t6/) ### Test 7 · ★ · wrong ✗ {#t7} What would you see if you looked at the back of a shiny spoon? - **1.** Yourself upside down and much smaller than you — no support - **2.** Nothing at all, because the back is too curved — no support - **3.** Yourself the right way up and spread out — **✓ the right answer** · no support - **4.** Only the colours of the rainbow, spread out — **← Mova's choice** · score 6 **Why:** It took the question to ask what it is done to. It chose option 4 with score 6, the only option with support. Its support: lesson 21, line 16: «Clouds are white because their droplets are much bigger than air molecules and scatter all colours equally; thick rain clouds look grey because little light ge…», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+3); the same action «scatter» (+2); the same thing acted on «colours» (+2). Against it: a different doer (counts against) (-1). The right option, 3, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t7/) ### Test 8 · ★ · right ✓ {#t8} Your mate says a mirror swaps left and right, so why doesn't it swap up and down? What is the real answer? - **1.** It swaps front and back, not left and right — **← Mova's choice** · **✓ the right answer** · score 5 - **2.** Mirrors only work sideways — no support - **3.** It does swap up and down if you wait — no support - **4.** Gravity stops it swapping up and down, but not sideways — no support **Why:** It took the question to ask why something happens (its cause). It chose option 1 with score 5, the only option with support. Its support: lesson 21, line 7: «A mirror does not really swap left and right; it swaps front and back, which makes writing look back to front.», reached through the option's own match among the sentences about the question's things. What matched: the same action «swap» (+3); the same thing acted on «front» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t8/) ### Test 9 · ★ · wrong ✗ {#t9} Which shows that white light is a mixture of colours? - **1.** A lamp switched off — **← Mova's choice** · no support - **2.** A shadow on the wall — no support - **3.** A mirror showing your face — no support - **4.** A prism spreading sunlight into a band of colours — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t9/) ### Test 10 · ★ · right ✓ {#t10} A shopkeeper puts a big curved mirror in the corner of the shop. Why curved? - **1.** To stop thieves from seeing their own faces — no support - **2.** To make all the goods on sale look shiny — score 1 - **3.** To make the whole shop look much smaller — score 1 - **4.** To show a wider view of the whole shop — **← Mova's choice** · **✓ the right answer** · score 8 **Why:** It took the question to ask why something happens (its cause). It chose option 4 with score 8, against 1 for the next best. Its support: lesson 21, line 10: «Car side mirrors and shop mirrors curve outwards to show a wider view.», reached through the cause of the sentence the question matched. What matched: the same thing acted on «wider view» (+5); the same action «show» (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t10/) ### Test 11 · ★ · wrong ✗ {#t11} You see a rainbow with the Sun low behind you in the evening. Which side of the sky is it in? - **1.** Underneath you, below the ground — **← Mova's choice** · no support - **2.** Straight up overhead, very high — no support - **3.** The side opposite the Sun — **✓ the right answer** · no support - **4.** The very same side as the Sun — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/t11/) ### Exam question 1 · formal language · wrong ✗ {#e1} Identify the principal cause of the blue colour of the daytime sky. - **1.** The emission of blue light alone by the Sun — **← Mova's choice** · no support - **2.** The reflection of the oceans upon the atmosphere — no support - **3.** The intrinsic blue colour of outer space — no support - **4.** The preferential scattering of blue light by the gases of the atmosphere — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/e1/) ### Exam question 2 · formal language · wrong ✗ {#e2} Which of the following statements most accurately characterises the formation of a rainbow? - **1.** Rainbows are formed solely by moonlight — **← Mova's choice** · no support - **2.** The Sun emits seven discrete beams of colour — no support - **3.** Coloured vapours are suspended within the clouds — no support - **4.** Sunlight is refracted, dispersed and reflected by droplets of water — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/e2/) ### Exam question 3 · formal language · wrong ✗ {#e3} It is given that an observer perceives a rainbow. Determine the position of the Sun relative to the observer. - **1.** Directly before the observer — **← Mova's choice** · no support - **2.** Below the horizon in front of the observer — no support - **3.** Directly overhead — no support - **4.** Behind the observer — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/e3/) ### Exam question 4 · formal language · right ✓ {#e4} Ascertain the reason for which a straight rod partially immersed in water appears bent. - **1.** The rod is deformed by the pressure of the water — no support - **2.** Light changes direction upon passing from water into air — **← Mova's choice** · **✓ the right answer** · score 13 - **3.** The eye cannot perceive objects beneath water — no support - **4.** The vessel distorts the rod mechanically by means of its curvature — no support **Why:** It took the question to ask which statement is true. It chose option 2 with score 13, the only option with support. Its support: lesson 21, line 17: «A straw in water looks bent because light changes direction as it passes from water into air, and herons aim carefully because a fish is not quite where it loo…», reached through the remembered sentence the question matched. What matched: the same circumstance (+5); the same place «water» (+4); the same action «pass» (+3); the same doer «light» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/21-mirrors-rainbows-and-the-blue-sky/e4/) - ← previous: [20. Light and shadows](https://md.mova.elamur.ai/free/en/school-run/physics/20-light-and-shadows/) - next →: [22. Lenses and eyes](https://md.mova.elamur.ai/free/en/school-run/physics/22-lenses-and-eyes/) - ↑ back to [Physics](https://md.mova.elamur.ai/free/en/school-run/physics/)