One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to
A. 800 K
B. 1000 K
C. 1200 K
D. 1400 K
Answer: Option A
Join The Discussion
Comments ( 7 )
Related Questions on Engineering Thermodynamics
Addition of heat at constant pressure to a gas results in
A. Raising its temperature
B. Raising its pressure
C. Raising its volume
D. Raising its temperature and doing external work
Which of the following items is not a path function?
A. Heat
B. Work
C. Kinetic energy
D. Thermal conductivity
An actual engine is to be designed having same efficiency as the Carnot cycle. Such a proposition is
A. Feasible
B. Impossible
C. Possible
D. Possible, but with lot of sophistications
The absolute zero pressure can be attained at a temperature of
A. 0°C
B. -273°C
C. 273 K
D. None of these
Short cut methods
√(1600•400)=40•20=800K
If there is two reversible heat engine or we can call it tapping cycle then there are two cases for determining the mid temperature...
1. If work done of both the heat engines are same
Then mid temperature(T2) is average of source temperature (1600K) and last heat engine's sink temperature (400K)
2. If efficiencies of both the heat engines are same then mid temperature (T2) is the geometric mean of source temperature (1600K) and last heat engine's sink temperature (400K).
Otherwise we can calculate combined
efficiency...
(1- eff. Of combined heat engine) = (1- eff. Of 1st engine ) (1-eff. Of 2nd engine)
We know all reversible engine have same efficiency when the same input so,
(1600-T2)/1600=(T2-400)/T2
Solve this,
We get
T2^2=640000
Then,
T2=√(640000)
T2= 800K
You know the Carnot rule that said all reversible engine have same efficiency so by using trail and error way easy to find the answer
One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to
A. 800 K
B. 1000 K
C. 1200 K
D. 1400 K
Please reply must
Please give explains how 800 k what is the rule and law