JEE Mains · Physics · STD 11 - 11. thermodynamics
A reversible engine has an efficiency of \(\frac{1}{4}\). If the temperature of the sink is reduced by \(58^{\circ} {C}\), its efficiency becomes double. Calculate the temperature of the sink. (In \(^{\circ} {C}\))
- A \(174\)
- B \(280\)
- C \(180.4\)
- D \(382\)
Answer & Solution
Correct Answer
(A) \(174\)
Step-by-step Solution
Detailed explanation
\({T}_{2}=\) sink temperature \(\eta=1-\frac{{T}_{2}}{{T}_{1}}\) \(\frac{1}{4}=1-\frac{{T}_{2}}{{T}_{1}}\) \(\frac{{T}_{2}}{{T}_{1}}=\frac{3}{4} \ldots\) \((i)\) \(\frac{1}{2}=1-\frac{{T}_{2}-58}{{T}_{1}}\) \(\frac{{T}_{2}}{{T}_{1}}-\frac{58}{{T}_{1}}=\frac{1}{2}\)…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A passenger train of length \(60\, m\) travels at a speed of \(80\, km/hr\). Another freight train of length \(120\, m\) travels at a speed of \(30\, km/hr\). The ratio of times taken by the passenger train to completely cross the freight train when: \((i)\) they are moving in the same direction, and \((ii)\) in the opposite directions isJEE Mains 2019 Hard
- A parallel plate capacitor has a capacitance \(\mathrm{C}=200 \mathrm{pF}\). It is connected to \(230 \mathrm{~V}\) ac supply with an angular frequency \(300 \mathrm{rad} / \mathrm{s}\). The \(\mathrm{rms}\) value of conduction current in the circuit and displacement current in the capacitor respectively are _______.JEE Mains 2024 Hard
- For the given circuit, the power across zener diode is ..... \({mW}.\)
JEE Mains 2021 Hard - Two planets \(A\) and \(B\) of radii \(R\) and \(1.5 R\) have densities \(\rho\) and \(\rho / 2\) respectively. The ratio of acceleration due to gravity at the surface of \(B\) to \(A\) is :JEE Mains 2023 Easy
- The fundamental frequency of vibration of a string stretched between two rigid support is \(50\,Hz\). The mass of the string is \(18\,g\) and its linear mass density is \(20\,g / m\). The speed of the transverse waves so produced in the string is \(..........\,ms ^{-1}\)JEE Mains 2023 Medium
- A metallic ring is uniformly charged as shown in figure. AC and BD are two mutually perpendicular diameters. Electric field due to \(\operatorname{arc} \mathrm{AB}\) to ' O ' is ' E ' is magnitude. What would be the magnitude of electric field at ' O ' due to arc ABC ?
JEE Mains 2025 Hard
More PYQs from JEE Mains
- The resistance \(R =\frac{ V }{ I },\) where \(V =(50 \pm 2) \;V\) and \(I=(20 \pm 0.2)\;A.\) The percentage error in \(R\) is \(x\%\). The value of \(x\) to the nearest integer is .........JEE Mains 2021 Medium
- A charge \(Q\) is moving \(\overrightarrow{dl}\) distance in the magnetic field \(\overrightarrow{ B }\). Find the value of work done by \(\overrightarrow{ B }\).JEE Mains 2021 Medium
- Light is incident on a metallic plate having work function \( 110\times10^{-20} \) J. If the produced photoelectrons have zero kinetic energy then the angular frequency of the incident light is __________ rad/s. (\( h=6.63\times10^{-34} \) J.s)JEE Mains 2026 Medium
- If \(a, b\) and \(c\) are the greatest value of \(^{19} \mathrm{C}_{\mathrm{p}},^{20} \mathrm{C}_{\mathrm{q}}\) and \(^{21 }\mathrm{C}_{\mathrm{r}}\) respectively, thenJEE Mains 2020 Hard
- The magnetic field in a travelling electromagnetic wave has a peak value of \(20\ n T\). The peak value of electric field strength is......\(Vm^{-1}\)JEE Mains 2013 Easy
- Assuming the validity of Bohr's atomic model for hydrogen like ions the radius of \(\mathrm{Li}^{++}\)ion in its ground state is given by \(\frac{1}{X} a_0\), where \(X=\) _______. (Where \(\mathrm{a}_0\) is the first Bohr's radius.)JEE Mains 2025 Easy