1 Physics -- Second Law of Thermodynamics

Why does a refrigerator consume more power in summer than in winter to cool the same quantity of food by the same degree?

1 Answers

Answer: Heat pumps are designed to move thermal energy opposite to the direction of spontaneous heat flow by absorbing heat from a cold space and releasing it to a warmer one. Due to surrounding temperature a refrigerator consume more power in summer than in winter to cool the same quantity of food by same degree.

A Carnot engine whose high-temperature reservoir is at 620 K takes in 550 J of heat at this temperature in each cycle and gives up 335 J to the low-temperature reservoir. (a) How much mechanical wo...

A Carnot engine whose high-temperature reservoir is at 620 K takes in 550 J of heat at this temperature in each cycle and gives up 335 J to the low-temperature reservoir. (a) How much mechanical work does the engine perform during each cycle? (b) What is

Solution:

Given,

Temperature of high-temperature reservoir (T1) = 620 K

Energy taken in each cycle (Q1) = 550 J

Energy given to low-temperature reservoir (Q2) = 335J

Now,

Mechanical work done in each cycle = Q1 - Q2

= 550 J - 335 J

= 215 J

Let the...

What happens to mileage per litre of diseal vehicle when it moves from hot terai to colder mustang?

The mileage per litre of diesel vehicles increases in moving from Terai to Mustang due to the decrease in surrounding temperature. With this, the density of air increases as we move from Terai to Mustang.

Does a refrigerator full of food consume more power if the room temperature is 20°C than if it is 15°C?

The efficiency of a refrigerator is expressed as:

Beta = T2 / (T1 - T2)

where T1 is the temperature of the source and T2 is the temperature of the sink. The smaller the value of (T1 - T2), the larger will be the efficiency of refrigerator. Hence, the refrigerator consumes more power when the room temperature is 20^oC than when it is 15^oC.

Q1. A measure of the degree of disorder of a system is known as Enthalpy Isobaric Isotropy EntropyQ2. If ΔThe efficiency of Carnot engine operating with reservior temperature at 100 K and –23 K wil...

1: A measure of the degree of disorder of a system is known asenthalpy.

2:If ΔThe efficiency of Carnot engine operating with reservior temperature at 100 K and –23 K will be(100+23)/100.

3:Coefficient of performance of an ideal refrigerator working between temperature T1 and T2 (T1 > T2) isBeta = T2 / (T1 - T2).

4:Entropy of a thermodynamic system does not change when this system is used for conduction of heat from a hot reservoir to a cold reservoir.

5:The second law of thermodynamics states...

7 .Which of the following is the largest unit of energy?electron voltjoulecalorieerg8. A perfect black body has a unique characteristic feature asa good absorber onlya good radiatora good absorber ...

7: Calorie is the largest unit of energy, among the given.

8: A perfect black body has a unique characteristic feature as a good absorber and a good radiator.

9: A thermodynamic process where no heat is exchanged with the surroundings is adiabatic.

10: Nernst formulated the Third law of thermodynamics.

11: The irreversibility of a process occurs due to either a) lack of equilibrium during the process or b) involvement of dissipative effects or both.

12: Efficiency of heat engine cycle is the ratio...

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