---
title: Ascertain the reason for which a compass ought not to be employed in… — Compasses and the magnetic Earth · tree and pragmatics
description: Ascertain the reason for which a compass ought not to be employed in proximity to a steel object. Exam question 2 of lesson 30 «Compasses and the magnetic Earth» of the physics course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice 
---

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# Exam question 2 · Compasses and the magnetic Earth

<!-- .ven lang=en -->
Ascertain the reason for which a compass ought not to be employed in proximity to a steel object.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 3 · wrong ✗ · **Who acts:** you · **What happens:** ascertain, not employ · **To what, where:** reason, compass, proximity

<!-- .vabout -->
This is exam question 2 of lesson 30 «Compasses and the magnetic Earth» of the physics course of Mova's primary school, asked in stiff, formal language. The page gives the question's syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause, then the 4 options as the student saw them, each with its tree and pragmatics. Every text is parsed by Mova itself. How the student answered it, with the score of every option and why: [the test at school](https://md.mova.elamur.ai/free/en/school-run/physics/30-compasses-and-the-magnetic-earth/#e2).

## The question {#question}

```conllu
# sent_id = question:physics:30-compasses-and-the-magnetic-earth:e2:1
# text = Ascertain the reason for which a compass ought not to be employed in proximity to a steel object.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	reason	reason	NOUN	NN	Number=Sing	1	obj	_	_
4	for	for	ADP	IN	_	5	case	_	_
5	which	which	PRON	WDT	PronType=Rel	12	obl	_	_
6	a	a	DET	DT	Definite=Ind|PronType=Art	7	det	_	_
7	compass	compass	NOUN	NN	Number=Sing	12	nsubj:pass	_	_
8	ought	ought	AUX	MD	VerbForm=Fin	12	aux	_	_
9	not	not	PART	RB	Polarity=Neg	12	advmod	_	_
10	to	to	PART	TO	_	12	mark	_	_
11	be	be	AUX	VB	VerbForm=Inf	12	aux:pass	_	_
12	employed	employ	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	3	acl:relcl	_	_
13	in	in	ADP	IN	_	14	case	_	_
14	proximity	proximity	NOUN	NN	Number=Sing	12	obl	_	_
15	to	to	ADP	IN	_	18	case	_	_
16	a	a	DET	DT	Definite=Ind|PronType=Art	18	det	_	_
17	steel	steel	NOUN	NN	Number=Sing	18	compound	_	_
18	object	object	NOUN	NN	Number=Sing	12	obl	_	SpaceAfter=No
19	.	.	PUNCT	.	_	1	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **ascertain** | imperative | you *not said here* | the reason |  |  |  |  | vn discover-84 «NP V NP»: agent=Agent reason=Topic |
| 2 | **not** **employ** | ought · passive | you *not said here* | a compass |  | proximity |  | for the reason; to a steel object | vn use-105.1 «NP V NP PP.predicate»: subject=Theme for which=Eventuality |

<!-- .note -->
One row per clause the reader finds. «not said here»: a role filled from the clause above. «roles by»: a VerbNet class and frame when one fits the verb, else the reader's rules on the tree.

## The options {#options}

### Option 1 · ← Mova's choice {#o1}

<!-- .ven lang=en -->
The steel reverses the direction of the Earth's rotation

```conllu
# sent_id = question:physics:30-compasses-and-the-magnetic-earth:e2:o1:1
# text = The steel reverses the direction of the Earth's rotation
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	steel	steel	NOUN	NN	Number=Sing	3	nsubj	_	_
3	reverses	reverse	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	direction	direction	NOUN	NN	Number=Sing	3	obj	_	_
6	of	of	ADP	IN	_	10	case	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	8	det	_	_
8	Earth	Earth	PROPN	NNP	Number=Sing	10	nmod:poss	_	SpaceAfter=No
9	's	's	PART	POS	_	8	case	_	_
10	rotation	rotation	NOUN	NN	Number=Sing	5	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **reverse** | present | the steel | the direction of the Earth's rotation |  |  |  |  | vn other\_cos-45.4 «NP V NP.patient»: agent=Agent direction=Patient |
| 2 | **rotate** |  | the Earth |  |  |  |  |  | nom rotation «act intransitive»: poss=agent |

### Option 2 {#o2}

<!-- .ven lang=en -->
The steel renders the needle too heavy to rotate

```conllu
# sent_id = question:physics:30-compasses-and-the-magnetic-earth:e2:o2:1
# text = The steel renders the needle too heavy to rotate
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	steel	steel	NOUN	NN	Number=Sing	3	nsubj	_	_
3	renders	render	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	needle	needle	NOUN	NN	Number=Sing	3	obj	_	_
6	too	too	ADV	RB	_	7	advmod	_	_
7	heavy	heavy	ADJ	JJ	Degree=Pos	5	amod	_	_
8	to	to	PART	TO	_	9	mark	_	_
9	rotate	rotate	VERB	VB	VerbForm=Inf	7	xcomp	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **render** | present | the steel | the needle |  |  |  |  | vn give-13.1 «NP V NP»: agent=Agent needle=Theme |
| 2 | **rotate** | to-infinitive | the steel *not said here* |  |  |  |  |  | vn modes\_of\_being\_with\_motion-47.3 «NP V»: agent=Theme |

### Option 3 · ✓ the right answer {#o3}

<!-- .ven lang=en -->
The steel exerts a stronger influence upon the needle than the Earth

```conllu
# sent_id = question:physics:30-compasses-and-the-magnetic-earth:e2:o3:1
# text = The steel exerts a stronger influence upon the needle than the Earth
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	steel	steel	NOUN	NN	Number=Sing	3	nsubj	_	_
3	exerts	exert	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	a	a	DET	DT	Definite=Ind|PronType=Art	6	det	_	_
5	stronger	strong	ADJ	JJR	Degree=Cmp	6	amod	_	_
6	influence	influence	NOUN	NN	Number=Sing	3	obj	_	_
7	upon	upon	ADP	IN	_	9	case	_	_
8	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
9	needle	needle	NOUN	NN	Number=Sing	3	obl	_	_
10	than	than	ADP	IN	_	12	case	_	_
11	the	the	DET	DT	Definite=Def|PronType=Art	12	det	_	_
12	Earth	Earth	PROPN	NNP	Number=Sing	9	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **exert** | present | the steel | a stronger influence |  |  |  | upon the needle than the Earth | vn use-105.1 «NP V NP»: agent=Agent influence=Theme |

### Option 4 {#o4}

<!-- .ven lang=en -->
The steel deprives the compass of the electrical supply upon which it depends

```conllu
# sent_id = question:physics:30-compasses-and-the-magnetic-earth:e2:o4:1
# text = The steel deprives the compass of the electrical supply upon which it depends
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	_	_
2	steel	steel	NOUN	NN	Number=Sing	3	nsubj	_	_
3	deprives	deprive	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	the	the	DET	DT	Definite=Def|PronType=Art	5	det	_	_
5	compass	compass	NOUN	NN	Number=Sing	3	obj	_	_
6	of	of	ADP	IN	_	9	case	_	_
7	the	the	DET	DT	Definite=Def|PronType=Art	9	det	_	_
8	electrical	electrical	ADJ	JJ	Degree=Pos	9	amod	_	_
9	supply	supply	NOUN	NN	Number=Sing	5	nmod	_	_
10	upon	upon	ADP	IN	_	11	case	_	_
11	which	which	PRON	WDT	PronType=Rel	13	obl	_	_
12	it	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	13	nsubj	_	_
13	depends	depend	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	9	acl:relcl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **deprive** | present | the steel | the compass of the electrical supply |  |  |  |  | vn deprive-10.6.2 «NP V NP»: agent=Agent compass=Source |
| 2 | **depend** | present | it |  |  |  |  | upon the electrical supply | vn rely-70 «NP V PP.theme S\_ING»: agent=Agent |

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**Text:** the tests of Mova's primary school, written for Mova (`world/data/school/`), as the course runner gave them to the student. **Trees:** Mova's own parse — the `en` model on the CPU, when the site is built — not checked by a teacher; they may be wrong. **Frames:** Mova's frames reader (`prag`), each text read on its own. Elamur Cosmic License.

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- ← previous: [Compasses and the magnetic Earth, exam 1](https://md.mova.elamur.ai/free/en/corpora/questions/physics/30-compasses-and-the-magnetic-earth/e1/)
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