Question

change. into passive voice who has broken the chair?

Answer 1

this chair was broken by whom ?
hope this will help you

Answer 2

By whom the chair has been broken?

(or)

The chair has been broken by whom?

Explanation:

An Interrogative sentence can be changed in passive form by adding the primary auxiliary verbs in the sentences.

Whereas, we have questions framed with questions tags like what, which, how are remained unchanged. But the questions beginning with who are interchanged with 'by whom'. The same way we had done in the above sentence.