A thermocouple is submerged in water contained inside a beaker of 5.0 cm diameter and a height of 7.0 cm. An immersion heater with a maximum power of 300 W is used to heat the water to the set temperature of 80°C. Calculate the steady-state temperature error for values of DT of 3, 5, and 10. Assume that the convective heat transfer coefficient between the beaker and environment is h = 45 W/m2K and the environment temperature is 25°C.

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.