Q) A closed chamber containing working refrigerator is pefectly

[kmp]

Q) A closed chamber containing working refrigerator is pefectly insulated and d door of refrigerator is opened, wat ll happen to temperature inside the chamber
a)Decrease
b) Remain same
c) Increased
d) Cant say coz it depends on quality of insulation

 

[kmp]

i think ,as the chamber is insulated so the temperature inside it should remain same, it will neither increase nor decrease. but i want a confirmed answer!

 

[yster]

It should decrease if the insulation is perfect which is exactly what the questions states. Think of the feeling you get when you stand a meter from your refrigerator then someone opens the door; cold air escapes from it and you can feel that cold air.

 

[S_Happens]

i think ,as the chamber is insulated so the temperature inside it should remain same, it will neither increase nor decrease. but i want a confirmed answer!

So post up your reasoning. My guess is that along with considering the room to be perfectly insulated, you're also supposed to ignore the fact that any real refrigeration cycle will produce heat that isn't available for the refrigeration (of course that assumption works best with common compressor style refrigerators, which is a safe bet).

It should decrease if the insulation is perfect which is exactly what the questions states. Think of the feeling you get when you stand a meter from your refrigerator then someone opens the door; cold air escapes from it and you can feel that cold air.

The "cold" air is not magically created. The heat removed from the inside of the fridge has to go somewhere, which is the point of this question.

 

[yster]

The "cold" air is not magically created. The heat removed from the inside of the fridge has to go somewhere, which is the point of this question.

Had to read that statement a couple of times to understand. I guess I just rushed into answering.

The compressor style refrigerants produce both heat and "cold" If there was a clear way to determine how much heat is removed compared to the heat added. If the total heat produced in the condensor is less that the heat absorbed in the evaporator then the temperature should decrease and vice versa.
The problem is more tricky than it seems. Given that the C.O.P is generally more than 1 I still believe the temperature should drop. It is easy to argue that it will stay the same, I don.t see it increasing though.

 

[256bits]

Do not forget the energy being added to the room via the electrical cord to power the refrigerator.

Think of the feeling you get when you stand a meter from your refrigerator then someone opens the door; cold air escapes from it and you can feel that cold air.

Think of the feeling you get from the back of the refrigerator also.

 

[kmp]

i agree with you all ,heat produced by the refrigerator can't be ignored, so its correct to say 'If the total heat produced in the condensor is less that the heat absorbed in the evaporator then the temperature should decrease '.
i was considering both the processes ,cooling and simultaneous production of heat equally, so that's why concluded that the temperature should remain same. But iam finding that yster's statement is explaining it properly!

 

[S_Happens]

Had to read that statement a couple of times to understand. I guess I just rushed into answering.

The compressor style refrigerants produce both heat and "cold" If there was a clear way to determine how much heat is removed compared to the heat added. If the total heat produced in the condensor is less that the heat absorbed in the evaporator then the temperature should decrease and vice versa.
The problem is more tricky than it seems. Given that the C.O.P is generally more than 1 I still believe the temperature should drop. It is easy to argue that it will stay the same, I don.t see it increasing though.

There is indeed a clear way to make the determination. I don't think you understand what the COP is representing. It is not the heat removed from the inside divided by the heat displaced to the outside. It is the ratio of heat removed from the inside to the work required to transfer it.

Do not forget the energy being added to the room via the electrical cord to power the refrigerator.

I was hoping the OP was going to walk us through their reasoning and stumble across this in the process.

 

[S_Happens]

i agree with you all ,heat produced by the refrigerator can't be ignored, so its correct to say 'If the total heat produced in the condensor is less that the heat absorbed in the evaporator then the temperature should decrease '.
i was considering both the processes ,cooling and simultaneous production of heat equally, so that's why concluded that the temperature should remain same. But iam finding that yster's statement is explaining it properly!

Yster's statements have not been correct. 256bits post should be the most useful to you. I was trying to offer less information and have you figure it out for yourself.

There is no sense in worrying about your "if" statement about the evaporator and condenser. These are easy enough to calculate, but not important to this question.