A black body has maximum wavelength 1 m at 2000 K. Its corresponding wavelength at 3000 K will be
- $ \frac{3}{2} \lambda m $
- $ \frac{2}{3} \lambda m $
- $ \frac{16}{81} \lambda m $
- $ \frac{81}{16} \lambda m $
The Correct Option is B
Solution and Explanation
$\lambda T = \, \, \, constant $
$\therefore \, \, \, \, {\lambda }' = (2/3) {\lambda }^m $
Top Questions on Heat Transfer
- Two spherical bodies of same materials having radii 0.2 m and 0.8 m are placed in same atmosphere. The temperature of the smaller body is 800 K and temperature of bigger body is 400 K. If the energy radiate from the smaller body is E, the energy radiated from the bigger body is (assume, effect of the surrounding to be negligible):
- JEE Main - 2025
- Physics
- Heat Transfer
Three conductors of same length having thermal conductivity \(k_1\), \(k_2\), and \(k_3\) are connected as shown in figure. Area of cross sections of 1st and 2nd conductor are same and for 3rd conductor it is double of the 1st conductor. The temperatures are given in the figure. In steady state condition, the value of θ is ________ °C. (Given: \(k_1\) = 60 Js⁻¹m⁻¹K⁻¹,\(k_2\) = 120 Js⁻¹m⁻¹K⁻¹, \(k_3\) = 135 Js⁻¹m⁻¹K⁻¹)
- JEE Main - 2025
- Physics
- Heat Transfer
- The temperature difference across two cylindrical rods A and B of same material and same mass are 40°C and 60°C respectively. In steady state, if the rates of flow of heat through the rods A and B are in the ratio 3 : 8, the ratio of the lengths of the rods A and B is:
- AP EAPCET - 2024
- Physics
- Heat Transfer
- A metal ball of mass 100 g at \( 20^\circ C \) is dropped in 200 ml of water at \( 80^\circ C \). If the resultant temperature is \( 70^\circ C \), then the ratio of specific heat of the metal to that of water is:
- AP EAMCET - 2024
- Physics
- Heat Transfer
- A metal block is made from a mixture of 2.4 kg of aluminium, 1.6 kg of brass, and 0.8 kg of copper. The metal block is initially at 20°C. If the heat supplied to the metal block is 44.4 calories, find the final temperature of the block if specific heats of aluminium, brass, and copper are 0.216, 0.0917, and 0.0931 cal.kg\(^{-1}\)°C\(^{-1}\) respectively.
- AP EAPCET - 2024
- Physics
- Heat Transfer
Questions Asked in NEET exam
- Given below are two statements :
Statement I : In the nephron, the descending limb of loop of Henle is impermeable to water and permeable to electrolytes.
Statement II : The proximal convoluted tubule is lined by simple columnar brush border epithelium and increases the surface area for reabsorption.
In the light of the above statements, choose the correct answer from the option given below :- NEET (UG) - 2024
- Nephrons
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The potential (V) at any axial point, at 2 m distance(r) from the centre of the dipole of dipole moment vector\(\vec{P}\) of magnitude, 4 × 10-6 C m, is ± 9 × 103 V.
(Take \(\frac{1}{4\pi\epsilon_0}=9\times10^9\) SI units)
Reason R : \(V=±\frac{2P}{4\pi \epsilon_0r^2}\), where r is the distance of any axial point, situated at 2 m from the centre of the dipole.
In the light of the above statements, choose the correct answer from the options given below :- NEET (UG) - 2024
- Magnetic Field
- \(^{290}_{82}X\stackrel{\alpha}{\rightarrow}Y\stackrel{e^+}{\rightarrow}Z\stackrel{\beta^-}{\rightarrow}P\stackrel{e^-}{\rightarrow}Q\)
In the nuclear emission stated above, the mass number and atomic number of the product Q respectively, are :- NEET (UG) - 2024
- Nuclear physics
- In an ecosystem if the Net Primary Productivity (NPP) of first trophic level is 100x (kcal m-2)yr-1, what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem?
- NEET (UG) - 2024
- Ecosystems
The output (Y) of the given logic gate is similar to the output of an/a :
- NEET (UG) - 2024
- Digital Electronics and Logic Gates
Concepts Used:
Heat Transfer
What is Heat Transfer?
It is defined as the movement of heat across the border of the system due to a difference in temperature between system and its surroundings.
How is Heat Transferred?
Heat can travel from one place to another in several ways. The different modes of heat transfer include:
- Conduction - Heat flows from things with higher temp to objects with lower temp.
- Convection - Movement of liquid molecules from higher temp regions to lower temp regions.
- Radiation - Radiant heat is present in every other way in our daily lives. Thermal radiations are also known to as radiant heat. Thermal radiation is generated by the emission of electromagnetic waves.
