Heat Transfer Questions

On observing light from three different stars P, Q and R, it was found that intensity of violet color is maximum in the spectrum of P, the intensity of green colour is maximum in the spectrum of R and...

The two ends of a metal rod are matainted at temperatures 100oC and 110oC. The rate of heat flow in the rod is found to be 4.0 J/s. If the ends are maintained at temperatures 200oC and 210oC, the rate...

A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K. If the radius were halved and the temperature doubled, the power radiated in watt would be :-

A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250nm is U1, at wavelength 500 nm is U2 and that at 1000 nm is U3. Wien’s constant, b = 2.88...

The power radiated by a black body is P and it radiates maximum energy at wavelength λ0. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength 34&#9...

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using :-...

Parallel rays of light of intensity I = 912 Wm-2 are incident on a spherical black body kept in surroundings of temperature 300 K. Take Stefan-Boltzmann constant σ = 5.7 × 10-8 Wm-2K-4 and ...

Certain quantity of water cools from 70oC to 60oC inthe first 5 minutes and to 54oC in the next 5 minutes. The temperature of the surroundings is...

Two rectangular blocks, having identical dimensions, can be arranged either in configuration I or in configuration II as shown in the figure. One of the blocks has thermal conductivity k and the other...

Three rods of copper, brass and steel are welded together to form a Y-shaped structure. Area of crossseciton of each rod = 4 cm2. End of copper rod is maintained at 100oC whereas ends of brass and ste...

An irregular rod of same uniform material as shown in figure is conducting heat at a steady rate. The temperature gradient at various sections versus area of cross section graph will be...

The figure below shows the variation of specific heat capacity (C) of a solid as a function of temperature (T). The temperature is increased continuously from 0 to 500 K at a constant rate. Ignoring a...

A cylinder of radius R made of a material of material of thermal conductivity K2 is surrounded by cylindrical shell of inner radius R and outer radius 2R made of a material of thermal conductivity K2....

three rods of identical cross-sectional area and made from the same material from the sides of an isoscales traangles ABC, right angled at B. The point A and B are maintained at temperatures T and (&#...

Two metallic spheres S1 and S2 are made of the same material and have got identical surface finish. The mass of S1 is thrice of S2. Both the spheres are heated to the same high temperature and placed ...

The intensity of radiation emitted by the sun has its maximum value at a wavelength of 510 nm and emitted by the north star has the maximum value at 350 nm. If these stars behave like blackbodies, the...

A spherical black body with a radius of 12 cm radiates 450 W power at 500 K. If the radius were halved and temperature doubled, the power radiated in watt would be

A black body is at temperature if 2800 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm...

An ideal black-body at room temperature is thrown into a furnace. It is observed that

The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by