"You know the committee structure works" is in active voice.
To change an active sentence to passive, identify the object in the active sentence and make it the subject in the passive sentence. Move the subject of the active sentence to the phrase with "by" and change the verb to its past participle form. To change a passive sentence to active, identify the subject in the passive sentence and make it the subject in the active sentence. Use an appropriate active verb to describe the subject's action and add the original object of the passive sentence as the direct object in the active sentence.
The sentence "Sentences can be written in active and passive voices" is a declarative sentence written in passive voice.
The verb "given" in the sentence "Were you given a second helping" is in the passive voice.
The sentence "The pen was missing" is in passive voice, as the subject (the pen) is receiving the action (being missing) rather than performing it.
The sentence is passive.
The sentence "All of the clues were carefully hidden by your teacher" is a passive sentence because the subject ("all of the clues") is being acted upon by the verb ("were hidden").
This is not an active sentence so it cannot be changed to a passive sentence. Active sentences have a subject and a verb. eg The dog chased the cat. As a passive sentence -- The cat was chased.
The sentence is active because the subject "the noon whistle" is performing the action of announcing lunchtime.
The mayor has given gifts to the pupils. -- active The pupils have been given gifts by the mayor -- passive Notice "the mayor" is the subject of the active sentence. In the passive sentence "the mayor' is the agent (by + agent). The object of the active sentence (the pupils) goes at the beginning of the passive sentence. The verb in the active sentence is present perfect, The passive form for present perfect is: have/has + been + past participle
The word decided is passive, because of the ed at the end, but if it was being used in a sentence, depending on how it was used in the sentence, it could be either active or passive. Hope that helps!
"a tap on a pole" is not a complete sentence. It does not contain a verb (a key component in active and passive voice), so it is neither active nor passive.
To change a sentence to a passive voice, you typically move the object of the active sentence to the subject position and introduce a form of the verb "to be" along with the past participle of the main verb. For example, changing "She wrote the report" (active) to "The report was written by her" (passive).