Is + past participle

Are these equivalent statements?

1a) There is a new phrase coined by some.

2a) There is a new phrase which has been coined by some.

Do these mean the same?

1b) A new phrase has been coined by some.

2b) A new phrase is coined by some.

Is it so that 2b requires an adverb to go with it as in 'A new phrase is coined by some every day'?