Consider the following statements:
I: Adiabatic demagnetization of a paramagnetic substances produces low temperature
II: Adiabatic produces a gas from a region of high pressure to a region of low pressure produces colling
III: A gas can be liquefied by applying high pressure above its critical temperature
Which of these statements is/are correct?
I only
I and II
I and III
II and III
The efficiency of an autmobile engine is 20% and it operates at 90 cycle per second. If it work at the rate of 120 hp, how much heat does the engine absorb per cycle?
4973 J
4450 J
4282 J
4000 J
What will be the work done by the refrigerator if the refrigerator has coefficient of performance = 4 and extracts heat from cold chamber at a rate of 252J per cycle?
-63 J
+63 J
-53 J
+53 J
What will be the minimum rate at which energy must be supplied to the heat pump, discharging heat inside a house, when the outside temperature is –10oC and the interior is to be kept at 22oC? (It is necessary to deliver heat at the rate of 16 k W to make up for normal heat losses.)
1.7 kW
16 kW
15 kW
2.7 kW
The rise in temperature when a gas is compressed suddenly to half of its original volume is_________
(Assume original temperature was 27oC and having = 1.5)
114.5oC
125oC
124.2oC
147.1oC
There is no degree of freedom or the system is invariant when the phase of the system co-exist.
Two
One
Three
None of the above
The Carnot engine is related to
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
None of the above
If two systems A and B are in thermal contact with one another and surrounded by adiabatic walls, then (where-H is heat energy transferred for system A, and H’ is heat energy transferred for system B)
H + H’ = 0
H – H’ = 0
H + 2H’ = 0
2H + H’ = 0
For a cyclic process the change in the internal energy of the system is
One
Zero
Maximum
Negative
Infrared emission from a body can be studied using a camera equipped with infrared sensitive film. The resulting picture is called a
Thermograph
Infra red camera
CCD (charge coupled device)
VCR