Which among the following equations represents the first law of thermodynamics under isobaric conditions ?

Options

A. `Delta U=q_p - P_(ex) * Delta V`
B. `q_(v) = Delta U`
C. `Delta V = W`
D. `W=-q`

Answer

A

Explanation

First law of thermodynamics is
`Delta U = q +W`
when p is constant i.e. isobari process,
`:." "Delta U = q_(p) - P_(ex)* Delta V`