MCQ
A thermodynamic system is taken form an initial state $i$ with internal energy $U_1=100 \ J$ to the final state along two different paths iaf and ibf, as schematically shown in the fire. The work done by the system along the paths $af$, ib and bf are $W _{ af }=200 \ J , W _{ ID }=50 \ J$ and $W _{ br }=100 \ J$ respectively. The heat supplied to the system along the path iaf, ib and bf are $Q_{\mid a t l} Q_{b r}$ and $Q_{10}$ respectively. If the internal energy of the sytem in the state $b$ is $U_b=$ $200 \ J$ and $Q_{l a t}=500 \ J$, the ratio $Q_{b J} / Q_{10}$ is:
  • A
    $1$
  • $2$
  • C
    $3$
  • D
    $4$

Answer

Correct option: B.
$2$
b
$w _{\text {lot }}=150 \ J $

$w _{\text {lat }}=200 \ J $

$Q _{\text {lat }}=500 \ J So U _{\text {lat }}=300 \ J$

So : $U_t=400 \ J$

$U_b=100 \ J $

$Q_b=100+50=150 \ J $

$Q_{b t}=300+150=450 \ J$

So the required ratio $\frac{Q_{b f}}{Q_{i b}}=\frac{450-150}{150}=2$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $I_1$ is the moment of inertia of a thin rod about an axis perpendicular to its length and passing through its centre of mass, and $I_2$ is the moment of inertia of the ring formed by bending the rod, then
An incandescent bulb has a thin filament of tungsten that is heated to high temperature by passing an electric current. The hot filament emits black-body radiation. The filament is observed to break up at random locations after a sufficiently long time of operation due to non-uniform evaporation of tungsten from the filament. If the bulb is powered at constant voltage, which of the following statement($s$) is(are) true?

($A$) The temperature distribution over the filament is uniform

($B$) The resistance over small sections of the filament decreases with time

($C$) The filament emits more light at higher band of frequencies before it breaks up

($D$) The filament consumes less electrical power towards the end of the life of the bulb

The angle between two vectors $ - 2\hat i + 3\hat j + \hat k$ and $\hat i + 2\hat j - 4\hat k$ is ....... $^o$
A body thrown vertically up with initial velocity $52 \,m / s$ from the ground passes twice a point at $h$ height above at an interval of $10 \,s$. The height $h$ is .........$m$ $\left(g=10 \,m / s ^2\right)$
A resonating column has resonant frequencies as $100Hz, 300Hz, 500Hz.$ Then it may:
During illness an $80\, kg$ man ran a fever of $102.2^o F$ instead of normal body temperature of $98.6^o F$. Assuming that human body is mostly water, how much heat is required to raise his temperature by that amount  .......... $kcal$ 
The velocity of projection of a body is increased by $2 \% .$ Other factors remaining unchanged, what will be the percentage change in the maximum height attained ? (in $\%$)
The radius of gyration of a uniform rod of length $L$ about an axis passing through its centre of mass and perpendicular to its length is:
If pressure of a gas contained in a closed vessel is increased by $0.4\%$ when heated by $1°C,$ the initial temperature must be
A body of mass $0.4\, kg$ is whirled in a vertical circle making $2\, rev/sec$. If the radius of the circle is $2\, m$, then tension in the string when the body is at the top of the circle, is ......... $N$