Ampul kırıldı.

Literally it reads The bulb was broken. Turkish forms the passive by inserting the suffix -ıl- / -ul- (depending on vowel harmony) between the verb stem and tense/aspect markers. Here:

• kır- = “to break” (root)
• -ıl- = passive voice marker
• -dı = past tense, 3rd person singular
  So kırıldı = “it was broken.” The noun ampul becomes the grammatical subject, even though no agent (person who broke it) is mentioned.

You switch to the active verb kırmak and mark the object:

• ampul → ampulü (accusative)
• kır- (root) + -dı (past tense)
  Hence: Ampulü kırdı.
  Here an implied “he/she” performed the action.

Yes. Use the agent phrase - tarafından after the doer’s name or noun:

• Ampul John tarafından kırıldı. = “The bulb was broken by John.”
  Or with a common noun:
• Ampul yanlışlıkla çocuklar tarafından kırıldı.

Both can refer to lighting equipment, but:

• ampul = the light bulb itself (the glass/electric component)
• lamba = the entire lamp fixture or light source (could be a bulb inside a housing)
  So if the glass bulb breaks, you say ampul kırıldı.

Phonetic hints (in broad transcription):

• ampul = [ˈampul] (like “AHM-pool”)
• kırıldı = [kɯˈɾɯldɯ]
  
  • ı = a back, unrounded vowel [ɯ], similar to the second vowel in English “roses” but tenser.
  • Stress falls on the syllable before the final, so kI-rIL-dı.

No intent is implied by passive voice; it simply states the result. Ampul kırıldı can describe an accident, negligence, or even purposeful breaking without specifying which. If you want to stress “by itself,” you could add kendiliğinden:

• Ampul kendiliğinden kırıldı. = “The bulb broke on its own.”