1
JEE Main 2015 (Offline)
MCQ (Single Correct Answer)
+4
-1
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A solid body of constant heat capacity $$1$$ $$J/{}^ \circ C$$ is being heated by keeping it in contact with reservoirs in two ways:
$$(i)$$ Sequentially keeping in contact with $$2$$ reservoirs such that each reservoir
$$\,\,\,\,\,\,\,\,$$supplies same amount of heat.
$$(ii)$$ Sequentially keeping in contact with $$8$$ reservoirs such that each reservoir
$$\,\,\,\,\,\,\,\,\,\,$$supplies same amount of heat.
In both the cases body is brought from initial temperature $${100^ \circ }C$$ to final temperature $${200^ \circ }C$$. Entropy change of the body in the two cases respectively is :
A
$$ln2, 2ln2$$
B
$$2ln2, 8ln2$$
C
$$ln2, 4ln2$$
D
$$ln2, ln2$$
2
JEE Main 2014 (Offline)
MCQ (Single Correct Answer)
+4
-1
One mole of a diatomic ideal gas undergoes a cyclic process $$ABC$$ as shown in figure. The process $$BC$$ is adiabatic. The temperatures at $$A, B$$ and $$C$$ are $$400$$ $$K$$, $$800$$ $$K$$ and $$600$$ $$K$$ respectively. Choose the correct statement : JEE Main 2014 (Offline) Physics - Heat and Thermodynamics Question 393 English
A
The change in internal energy in whole cyclic process is $$250$$ $$R.$$
B
The change in internal energy in the process $$CA$$ is $$700$$ $$R$$.
C
The change in internal energy in the process $$AB$$ is - $$350$$ $$R.$$
D
The change in internal energy in the process $$BC$$ is - $$500$$ $$R.$$
3
JEE Main 2014 (Offline)
MCQ (Single Correct Answer)
+4
-1
Three rods of Copper, Brass and Steel are welded together to form a $$Y$$ shaped structure. Area of cross - section of each rod $$ = 4c{m^2}.$$ End of copper rod is maintained at $${100^ \circ }C$$ where as ends of brass and steel are kept at $${0^ \circ }C$$. Lengths of the copper, brass and steel rods are $$46,$$ $$13$$ and $$12$$ $$cms$$ respectively. The rods are thermally insulated from surroundings excepts at ends. Thermal conductivities of copper, brass and steel are $$0.92, 0.26$$ and $$0.12$$ $$CGS$$ units respectively. Rate of heat flow through copper rod is:
A
$$1.2$$ $$cal/s$$
B
$$2.4$$ $$cal/s$$
C
$$4.8$$ $$cal/s$$
D
$$6.0$$ $$cal/s$$
4
JEE Main 2013 (Offline)
MCQ (Single Correct Answer)
+4
-1
JEE Main 2013 (Offline) Physics - Heat and Thermodynamics Question 394 English

The above $$p$$-$$v$$ diagram represents the thermodynamic cycle of an engine, operating with an ideal monatomic gas. The amount of heat, extracted from the source in a single cycle is

A
$${p_0}{v_0}$$
B
$$\left( {{{13} \over 2}} \right){p_0}{v_0}$$
C
$$\left( {{{11} \over 2}} \right){p_0}{v_0}$$
D
$$4{p_0}{v_0}$$
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