Question

The first law of thermodynamics states that the change U in the internal energy of a system is given by U Q W, where Q is the heat and W is the work. Both Q and W can be positive or negative numbers. Q is a positive number if ________, and W is a positive number if ________. (a) the system loses heat; work is done by the system (b) the system loses heat; work is done on the system (c) the system gains heat; work is done by the system (d) the system gains heat; work is done on the system

Answer 1

Answer:

d

Explanation:

First law of thermodynamics

 It is also known as energy conservation law.It state that net work in a cyclic process is equal to net heat in that cycle.

From first law

Q=ΔU + W

ΔU = Q - W

ΔU is the change in internal energy of gas.

Q is heat transfer from the system or to the system.

W is the work done by the system or on the system.

If work done on the system then it will be taken as positive and If work done by the system then it will be taken as negative.

If heat taken by system it will taken as positive and If heat rejected by system it will taken as negative.

So Q will be positive if system gains heat and work will be positive if work is done on the system.