In a closed insulated container a liquid is stirred with a paddle to increase the temperature which of the following is true

Options

(a) ΔE = w ≠ 0, q = 0
(b) ΔE = w = q ≠ 0
(c) ΔE = 0, w = q ≠ 0
(d) w = 0, ΔE = q ≠ 0

Correct Answer:

ΔE = w ≠ 0, q = 0

Explanation:

The mathematical form of first law of thermodynamics : q = ΔE + W, Since the system is closed and insulated, q = 0, Paddle work is done on system. Therefore W ≠ 0. Temperature and hence internal energy of the system increases. Therefore ΔE ≠ 0.