COMEDK · Physics · 12. Thermal Properties of Matter
A block of metal A is connected in series with another block of metal B such that the two metal blocks have the same area of cross sections. The thermal conductivity of metal A is K and the free end of metal A is at \(80^{\circ} \mathrm{C}\). The temperature of the interface is \(60^{\circ} \mathrm{C}\) and the free end of metal B is at \(20^{\circ} \mathrm{C}\). Assuming the two metals have the same thickness, the conductivity of metal B is:
- A \(2 K\)
- B \(\dfrac{K}{2}\)
- C \(\dfrac{K}{4}\)
- D \(4 K\)
Answer & Solution
Correct Answer
(B) \(\dfrac{K}{2}\)
Step-by-step Solution
Detailed explanation
In a steady state, the rate of heat flow through two blocks connected in series is the same. Let \(A\) be the cross-sectional area and \(L\) be the thickness of each block. The rate of heat flow \(H\) is given by \(H = \dfrac{KA(T_1 - T_2)}{L}\). For metal A, the temperature…
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 parallel plate capacitor has a capacity \(C\). The separation between the plates is doubled and a dielectric medium is inserted between the plates. If the capacity is \(3 C\), then the dielectric constant of the medium will beCOMEDK 2015 Medium
- Two particles of masses \(m_{1}=m, m_{2}=2 m\) and charges \(q_{1}=q, q_{2}=2 q\) entered into uniform magnetic field with the same velocity and at the same angle. Find \(F_{1} / F_{2}\) (force ratio).COMEDK 2021 Easy
- The focal lengths of the objective and eyepiece of a compound microscope are 1 cm and 10 cm respectively. Length of the tube is 25 cm . If the final image is formed at infinity, the magnifying power of the microscope is:COMEDK 2025 Medium
- The speeds of air-flow on the upper and lower surfaces of a wing of an aeroplane \(arefv_1\) and \(v_2\), respectively. If \(A\) is the cross-sectional area of the wing and \(\rho\) is the density of air, then the upward lift isCOMEDK 2023 Easy
- An electron is accelerated through a potential difference of \(45.5 \mathrm{~V}\). The velocity acquired by it is \(\left(\right.\) in \(\mathrm{ms}^{-1}\) )COMEDK 2013 Easy
- A particle of mass \(m\) is kept at rest at a height \(3 R\) from the surface of earth, where \(R\) is radius of earth and \(M\) is mass of earth. The minimum speed with which it should be projected, so that it does not return back, is ( \(g\) is acceleration due to gravity on the surface of earth)COMEDK 2013 Hard
More PYQs from COMEDK
- A die is thrown twice and the sum of numbers appearing is observed to be 8 . What is the conditional probability that the number 5 has appeared atleast once?COMEDK 2023 Medium
- A body is moving along a circular path of radius '\(r\)' with a frequency of revolution numerically equal to the radius of the circular path. What is the acceleration of the body if radius of the path is \(\left(\dfrac{5}{\pi}\right) m\) ?COMEDK 2024 Medium
- Which mirror is to be used to obtain a parallel beam of light from a small lamp?COMEDK 2017 Easy
- A lens of power \(+1 \mathrm{D}\) is made in contact with another lens of power \(-2 \mathrm{D}\) the combination will then act as a:COMEDK 2023 Easy
- The solution which have lowest freezing point isCOMEDK 2022 Medium
- If \(A=\left[\begin{array}{ll}3 & 4 \\ 1 & 2\end{array}\right]\), then \(A^{-1}\) equal toCOMEDK 2024 Easy