In a closed insulated container, a liquid is stirred with a paddle to increase the temperature. Which of the following is true?

Options

A. `Delta U = W != 0, q = 0`
B. `Delta U = W != 0 = q != 0`
C. `Delta U = 0,W = 0, q != 0`
D. `U = Delta U = q != 0`

Answer

A

Explanation

In a closed insulated container, no heat can enter or leave the system, thus, `q = 0`. Due increase of temperature, `Delta U != 0`. According to the first law of the thermodynamics,
`Delta U = q + W`
`= 0 + W`
`W != 0`