Question

What is the minimum work required of a refrigerator if it is to extract 50 J per cycle from the inside of a freezer at −10°C and exhaust heat to the air at 25°C?

a) 25 J
b) 50 J
c) 75 J
d) 100 J

Answer 1

The minimum work required of the refrigerator is 50 J.

Step-by-step explanation:

The minimum work required of a refrigerator can be found using the formula:

Qc / W = Tc / (Th - Tc)

Where:

• Qc is the heat removed from the cold reservoir (in this case, 50 J)
• W is the work done by the refrigerator (what we're trying to find)
• Tc is the temperature of the cold reservoir (-10 ℃)
• Th is the temperature of the hot reservoir (25 ℃)

Plugging the values into the formula, we get:

(50 J) / W = (-10 ℃) / (25 ℃ - (-10 ℃))

Simplifying this equation will give us the minimum work required of the refrigerator, which is 50 J.