JEE Mains · Physics · STD 11 - 10.2 transmission of heat
In \(5\, minutes,\) a body cools from \(75^{\circ} {C}\) to \(65^{\circ} {C}\) at room temperature of \(25^{\circ} {C}\). The temperature of body at the end of next \(5\, minutes\) is \(......\,{ }^{\circ} {C} .\)
- A \(57\)
- B \(60\)
- C \(61\)
- D \(570\)
Answer & Solution
Correct Answer
(A) \(57\)
Step-by-step Solution
Detailed explanation
By newton's law of cooling (with approximation) \(\frac{\Delta {T}}{\Delta {t}}=-{C}\left({T}_{{avg}}-{T}_{{s}}\right)\) \(1^{\text {st }}\, \frac{-10^{\circ} {C}}{5\, {min}}=-{C}\left(70^{\circ} {C}-25^{\circ} {C}\right)\) \({C}=\frac{2}{45}\, {min}^{-1}\)…
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
- Two identical positive charges \(Q\) each are fixed at a distance of ' \(2 a\) ' apart from each other. Another point charge qo with mass ' \(m\) ' is placed at midpoint between two fixed charges. For a small displacement along the line joining the fixed charges, the charge \(q_{0}\) executes \(SHM\). The time period of oscillation of charge \(q_{0}\) will be.JEE Mains 2022 Hard
- The recoil speed of a hydrogen atom after it emits a photon in going from \(n =5\) state to \(n =1\) state will be ..... \(m/s\)JEE Mains 2021 Hard
- A lens having refractive index 1.6 has focal length of 12 cm , when it is in air. Find the focal length of the lens when it is placed in water.
(Take refractive index of water as 1.28)JEE Mains 2025 Easy - Resistance of the wire is measured as \(2\,\Omega\) and \(3\,\Omega\) at \(10^{\circ}C\) and \(30^{\circ}C\) respectively. Temperature cocoefficient of resistance of the material of the wire is............\(^{\circ}C ^{-1}\)JEE Mains 2022 Medium
- A wheel initially at rest is subjected to a uniform angular acceleration about its axis. In the first \(2\text{ s}\) it rotates through an angle \(\theta_1\) and in the next \(2\text{ s}\) it rotates through an angle \(\theta_2\). The ratio \(\dfrac{\theta_2}{\theta_1}\) is _______.JEE Mains 2026 Medium
- Given below are two statements: Statement \(I :\) \(PN\) junction diodes can be used to function as transistor, simply by connecting two diodes, back to back, which acts as the base terminal. Statement \(II :\) In the study of transistor, the amplification factor \(\beta\) indicates ratio of the collector current to the base current. In the light of the above statements, choose the correct answer from the options given below :JEE Mains 2021 Medium
More PYQs from JEE Mains
- The equivalent resistance of the given circuit between the terminals \({A}\) and \({B}\) is \(....\Omega\)
JEE Mains 2021 Hard - A charge of \(4.0 \mu \mathrm{C}\) is moving with a velocity of \(4.0 \times 10^6 \mathrm{~ms}^{-1}\) along the positive \(\mathrm{y}\)-axis under a magnetic field \(\vec{B}\) of strength \((2 \hat{k})\ T\). The force acting on the charge is \(x \hat{i} N\). The value of \(x\) is _______.JEE Mains 2024 Hard
- A train is moving on a straight track with speed \(20\ ms^{-1}\). It is blowing its whistle at the frequency of \(1000\ Hz\). The percentage change in the frequency heard by a person standing near the track as the train passes him is ( speed of sound \(=320\) \(ms^{-1}\) ) close to .... \(\%\)JEE Mains 2015 Hard
- Consider the function \(\mathrm{f}:(0,2) \rightarrow \mathrm{R}\) defined by \(f(x)=\frac{x}{2}+\frac{2}{x}\) and the function\( g(x)\) defined by \(g(x)=\left\{\begin{array}{cc}\min \{f(t)\}, & 0 < t \leq x \text { and } 0 < x \leq 1 \\ \frac{3}{2}+x, & 1 < x< 2\end{array}\right.\). ThenJEE Mains 2024 Hard
- In a parallel plate capacitor set up, the plate area of capacitor is \(2 \,m ^{2}\) and the plates are separated by \(1\, m\). If the space between the plates are filled with a dielectric material of thickness \(0.5\, m\) and area \(2\, m ^{2}\) (see \(fig.\)) the capacitance of the set-up will be \(.........\, \varepsilon_{0}\) (Dielectric constant of the material \(=3.2\) ) and (Round off to the Nearest Integer)
JEE Mains 2021 Hard - Consider function \(f: A \rightarrow B\) and \(g: B \rightarrow C(A, B, C \subseteq R)\) such that \((gof) ^{-1}\) exists, then:JEE Mains 2021 Medium