1
AIEEE 2012
+4
-1
Out of Syllabus
A Carnot engine, whose efficiency is $$40\%$$, takes in heat from a source maintained at a temperature of $$500$$ $$K.$$ It is desired to have an engine of efficiency $$60\% .$$ Then, the intake temperature for the same exhaust (sink) temperature must be :
A
efficiency of Carnot engine cannot be made larger than $$50\%$$
B
$$1200$$ $$K$$
C
$$750$$ $$K$$
D
$$600$$ $$K$$
2
AIEEE 2012
+4
-1
Helium gas goes through a cycle $$ABCD$$ (consisting of two isochoric and isobaric lines) as shown in figure efficiency of this cycle is nearly : (Assume the gas to be close to ideal gas)
A
$$15.4\%$$
B
$$9.1\%$$
C
$$10.5\%$$
D
$$12.5\%$$
3
AIEEE 2012
+4
-1
A wooden wheel of radius $$R$$ is made of two semicircular part (see figure). The two parts are held together by a ring made of a metal strip of cross sectional area $$S$$ and length $$L.$$ $$L$$ is slightly less than $$2\pi R.$$ To fit the ring on the wheel, it is heated so that its temperature rises by $$\Delta T$$ and it just steps over the wheel. As it cools down to surrounding temperature, it process the semicircular parts together. If the coefficient of linear expansion of the metal is $$\alpha$$, and its Young's modulus is $$Y,$$ the force that one part of the wheel applies on the other part is :
A
$$2\pi SY\alpha \Delta T$$
B
$$SY\alpha \Delta T$$
C
$$\pi SY\alpha \Delta T$$
D
$$2SY\alpha \Delta T$$
4
AIEEE 2011
+4
-1
Out of Syllabus
A Carnot engine operating between temperatures $${{T_1}}$$ and $${{T_2}}$$ has efficiency $${1 \over 6}$$. When $${T_2}$$ is lowered by $$62$$ $$K$$ its efficiency increases to $${1 \over 3}$$. Then $${T_1}$$ and $${T_2}$$ are, respectively:
A
$$372$$ $$K$$ and $$330$$ $$K$$
B
$$330$$ $$K$$ and $$268$$ $$K$$
C
$$310$$ $$K$$ and $$248$$ $$K$$
D
$$372$$ $$K$$ and $$310$$ $$K$$
EXAM MAP
Medical
NEET