Mıknatıs kadranın altında bulundu.

Because altında is built from the noun alt (the bottom, lower part) and it usually combines with a noun before it in the genitive form.

So:

• kadran = dial
• kadranın = of the dial
• altı = its bottom / the space under it
• kadranın altı = the dial’s lower part / the area under the dial
• kadranın altında = under the dial

This is a very common Turkish pattern with location words like:

• üstünde = on top of
• altında = under
• içinde = inside
• önünde = in front of
• arkasında = behind

So kadranın altında literally works like at the dial’s underside / under the dial.

Altında can be broken down like this:

• alt = bottom, lower part
• -ı = third-person possessive suffix, roughly its
• -nda = locative ending, in/on/at

So:

• altı = its lower part / its underside
• altında = at its lower part, under it

In the full phrase kadranın altında, the meaning is under the dial.

This structure is very normal in Turkish. These words often look like nouns rather than simple prepositions, even though in English we translate them with prepositions like under, on, behind, etc.

Yes. Turkish word order is flexible, although the verb usually comes last.

This sentence has:

• Mıknatıs = subject
• kadranın altında = location
• bulundu = verb

That is a very natural order.

But Turkish could also say:

• Kadranın altında mıknatıs bulundu.

That would still be grammatical. Moving parts around changes emphasis more than basic meaning.
The most important thing is that bulundu stays at the end in a normal statement.

Bulundu is the past tense form of bulunmak.

Depending on context, bulunmak can mean:

• to be found
• to be located
• to be present

So bulundu can mean:

• was found
• was located
• was present

In this sentence, the exact English translation depends on context. If someone was searching for the magnet, was found is natural. If it is simply describing location, was located may fit better.

It can feel passive in English translation, but in Turkish it is best understood here as the past tense of bulunmak.

Compare:

• bulmak = to find
• bulunmak = to be found / to be located

So the sentence is not built like an English-style passive with a separate helper verb. Instead, Turkish has the verb bulunmak, which already carries that meaning.

That is why bulundu can naturally translate as was found or was located.

Turkish normally does not use articles like the or a/an.

So:

• mıknatıs can mean magnet, a magnet, or the magnet
• kadranın altında can mean under the dial

Which one sounds best in English depends on context.

Turkish often leaves definiteness to context, while English usually has to choose an article.

Because mıknatıs is the subject of the sentence, so it stays in its basic dictionary form.

Turkish usually marks the object more clearly than the subject.
Since the magnet is the thing being talked about as the subject of bulundu, no extra case ending is needed.

So:

• mıknatıs = the magnet / a magnet
• basic form, acting as the subject

Normally, with alt, üst, ön, arka, iç and similar words used this way, Turkish prefers the genitive-possessive pattern:

• kadranın altında
• masanın üstünde
• evin önünde

So kadran altında would not be the standard form here.

The usual pattern is:

[noun in genitive] + [location noun with possessive + case]

That is why kadranın altında is the expected wording.

The Turkish ı is a very common sound for English speakers to practice because it does not equal English i.

A rough guide:

• i in Turkish is like ee in see
• ı is a deeper, more central vowel, with no exact English equivalent

So:

• mıknatıs is approximately muhk-nah-tuhs, but that is only a rough guide
• both ı sounds are the same Turkish ı
• the stress is usually near the end: mıknaTIS

Also:

• kadranın has ı in the last syllable too
• altında also contains ı

This sentence is a good example of how frequent ı is in Turkish.

It is the simple past tense.

The ending is:

• -du / -dı / -dü / -di (with vowel harmony and consonant changes)

Here:

• bulun-
  • -du → bulundu

So the sentence describes something in the past:

• the magnet was found
• the magnet was located

In English, under is just a preposition.
In Turkish, altında comes from a noun-based structure.

So instead of thinking of it as a single preposition, it is better to think:

• alt = lower part
• altı = its lower part
• altında = at its lower part / under it

This is why Turkish uses forms like:

• masanın altında = under the table
• kutunun içinde = inside the box
• evin önünde = in front of the house

For an English speaker, this can feel unusual at first, but it is one of the most important patterns in Turkish.