Question
A Carnot engine operating between two reservoirs has efficiency $\frac{1}{3}$. When the temperature of cold reservoir raised by $x$, its efficiency decreases to $\frac{1}{6}$. The value of $x$, if the temperature of hot reservoir is $99^{\circ}\,C$, will be $........\,K$

Answer

$T _{ H }=99^{\circ} C =99+273$

$\qquad=372\,K$

$1-\frac{ T _{ C }}{ T _{ H }}=\frac{1}{3}$

$\frac{ T _{ C }}{ T _{ H }}=\frac{2}{3} \quad(1) \Rightarrow T _{ C }=\frac{2}{3} \times 372$

$1-\frac{ T _{ C }+ X }{ T _{ H }}=\frac{1}{6}$

$\frac{5}{6}=\frac{ T _{ C }+ X }{ T _{ H }}$

$\frac{5}{6}=\frac{248+ X }{372}$

$248+ X =5 \times 62$

$X =310-248=62\,K$

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

A wheel of moment of inertia $10\ kg-m^2$ is rotating at $10$ rotations per minute. The work done in increasing its speed to $5$ times its initial value, will be.......... $J$
A single wire $ACB$ passes through a smooth ring at $C$ which revolves at a constant speed in the horizontal circle of radius $r$ as shown in the figure. The speed of revolution is
The position of the centre of mass of a uniform semi-circular wire of radius $'R'$ placed in $x-y$ plane with its centre at the origin and the line joining its ends as $x$-axis is given by $\left(0, \frac{x R}{\pi}\right)$.

Then, the value of $|x|$ is ...... .

A system $S$ receives heat continuously from an electrical heater of power $10W$. The temperature of S becomes constant at $50^o C$ when the surrounding temperature is $20^o C$. After the heater is switched off, $S$ cools from $35.1^o C$ to $34.9^o C$ in $1$ minute. The heat capacity of $S$ is........ $ J/^oC$
A capillary tube is attached horizontally to a constant head arrangement. If the radius of the capillary tube is increased by $10\%$ then the rate of flow of liquid will change nearly by ......... $\%$
Which one statement is correct ? A parallel plate air condenser is connected with a battery. Its charge, potential, electric field and energy are ${Q_o},\;{V_o},\;{E_o}$ and ${U_o}$ respectively. In order to fill the complete space between the plates a dielectric slab is inserted, the battery is still connected. Now the corresponding values $Q,\;V,\;E$ and $U$ are in relation with the initially stated as
The equivalent resistance and potential difference between $A$ and $B$ for the circuit is respectively
A swimmer wants to cross a river from point $A$ to point $B$. Line $A B$ makes an angle of $30^{\circ}$ with the flow of river. Magnitude of velocity of the swimmer is same as that of the river. The angle $\theta$ with the line ${AB}$ should be $^{\circ}$, so that the swimmer reaches point ${B}$.
If a photon has velocity $c$ and frequency $\nu$, then which of following represents its wavelength
$PN-$junction diode works as a insulator, if connected