A reversible engine converts one-sixth of the heat input into wor… - Vidyadip

MCQ

A reversible engine converts one-sixth of the heat input into work. When the temperature of the sink is reduced by $62^{\circ} \mathrm{C}$, the efficiency of the engine is doubled. The temperatures of the source and sink are

A
$80^{\circ} \mathrm{C}, 37^{\circ} \mathrm{C}$
B
$95^{\circ} \mathrm{C}, 28^{\circ} \mathrm{C}$
C
$90^{\circ} \mathrm{C}, 37^{\circ} \mathrm{C}$
✓
$99^{\circ} \mathrm{C}, 37^{\circ} \mathrm{C}$

✓

Answer

Correct option: D.

$99^{\circ} \mathrm{C}, 37^{\circ} \mathrm{C}$

(d)Initially $\eta=\left(1-\frac{T_2}{T_1}\right)=\frac{W}{Q}=\frac{1}{6}$
Finally $(\eta^\prime)=(1-\frac{T_2^\prime}{T-1}) =\left(1\frac{(T_2)-62}{T_1}\right)=1\frac{T_2}{T_1}+\frac{62}{T_1}$
$=\eta+\frac{62}{T_1}$It is given that $\eta^{\prime}=2 \eta$.
Hence solving equation (i) and (ii)
$\Rightarrow T_1=372 \mathrm{~K}=99^{\circ} \mathrm{C}$ and $T_2=310 \mathrm{~K}=37^{\circ} \mathrm{C}$

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

Explore more

More "MCQ" from Thermodynamics→Thermodynamics — all question types→JEE physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

A galvanometer coil has a resistance $90\, \Omega$ and full scale deflection current $10\, mA$ . A $910\,\Omega$ resistance is connected in series with the galvanometer to make a voltmeter. If the least count of the voltmeter is $0.1\,V$, the number of divisions on its scale is

If the K.E. of a body is increased by $300 \%$, its momentum will increase by

When a body moves with a constant speed along a circle

The potential gradient along the length of a uniform wire is 10 volt/metre. $B$ and $C$ are the two points at $30 \mathrm{~cm}$ and $60 \mathrm{~cm}$ point on a meter scale fitted along the wire. The potential difference between $B$ and $C$ will be

The resistance of a germanium junction diode whose $V-I$ is shown in figure is $\left(V_k=0.3 V \right)$

Consider a galvanometer shunted with $5\, \Omega$ resistance and $2\, \%$ of current passes through it.

What is the resistance of the given galvanometer? (In $\Omega$)

A particle starts from rest. Its acceleration versus time $(t)$ is as shown in the figure. The maximum speed of the particle will be

The r.m.s. voltage of domestic electricity supply is $220$ volt . Electrical appliances should be designed to withstand an instantaneous voltage of

Two coherent sources $S$ and $S$ are separated by a distance four times the wavelength $\lambda$ of the source. The sources lie along $y$ axis whereas a detector moves along $+x$ axis. Leaving the origin and far off points the number of points where maxima are observed is

If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of container is