The predicate calculus extends the propositional calculus by adding quantifiers such as 'all' (written with an upside-down 'A') and 'some' (written with a backwards 'E').

Yes.

The Ohm's law is defined as voltage propositional to current. The equation given by

V=IR

R IS THE PROPOSITIONAL CONSTANT

The object of the propositional phrase "from head" depends on the context in which it is used. It can mean someone is thinking or acting without careful consideration, or it can refer to something originating from a particular source or starting point.

"A propositional phrase acts as a single part of speech, made up of a preposition and its object."