containing/contains, formed/is formed

English as a Second Language English Vocabulary, Grammar and Idioms
1

FIGURE 6.5(a) Circuit containing a current source, two resistors, and a switch; (b) linear subcircuit formed when the switch is in the ON state; © linear sub-circuit formed when the switch is in the OFF state.

FIGURE 6.5(a) Circuit contains a current source, two resistors, and a switch; (b) linear subcircuit is formed when the switch is in the ON state; © linear sub-circuit is formed when the switch is in the OFF state.

Is #2 also correct?
If so which one do you prefer to?

2

The first version is preferable in my opinion. Noun phrases are all that is required here; there is no need for full statements with finite verbs.

3

Thanks for your opinion!
To be sure, do you think that #2 is wrong in this case?

4

No, it is not actually wrong.