Advertisements
Advertisements
प्रश्न
Compare the rate of radiation of metal bodies at 727 °C and 227 °C.
Advertisements
उत्तर
Given:
T1 = 727 °C = 727 + 273 = 1000 K,
T2 = 227 °C = 227 + 273 = 500 K
To find: Ratio of radiation `[((dQ)/dt)_1/((dQ)/dt)_2]`
Formula:
`(dQ)/dt = σAeT^4`
Calculation:
From formula,
`((dQ)/dt)_1 = σAeT_1^4` ...............(1)
`((dQ)/dt)_2 = σAeT_2^4` ...............(2)
Dividing equation (1) by (2),
`((dQ)/dt)_1/((dQ)/dt)_2 = (σAeT_1^4)/(σAeT_2^4) = (T_1/T_2)^4`
= `(1000)^4/(500)^4 = 16`
The rate of radiation of the metal sphere at 727 °C and 227 °C is 16:1.
APPEARS IN
संबंधित प्रश्न
When we place a gas cylinder on a van and the van moves, does the kinetic energy of the molecules increase? Does the temperature increase?
Do you expect the gas in a cooking gas cylinder to obey the ideal gas equation?
Can we define the temperature of (a) vacuum, (b) a single molecule?
Comment on the following statement: the temperature of all the molecules in a sample of a gas is the same.
Consider a gas of neutrons. Do you expect it to behave much better as an ideal gas as compared to hydrogen gas at the same pressure and temperature?
If the molecules were not allowed to collide among themselves, would you expect more evaporation or less evaporation?
The pressure of an ideal gas is written as \[P = \frac{2E}{3V}\] . Here E refers to
The mean square speed of the molecules of a gas at absolute temperature T is proportional to
Which of the following quantities is the same for all ideal gases at the same temperature?
(a) The kinetic energy of 1 mole
(b) The kinetic energy of 1 g
(c) The number of molecules in 1 mole
(d) The number of molecules in 1 g
A gas cylinder has walls that can bear a maximum pressure of 1.0 × 106 Pa. It contains a gas at 8.0 × 105 Pa and 300 K. The cylinder is steadily heated. Neglecting any change in the volume, calculate the temperature at which the cylinder will break.
Figure shows a cylindrical tube of radius 5 cm and length 20 cm. It is closed by a tight-fitting cork. The friction coefficient between the cork and the tube is 0.20. The tube contains an ideal gas at a pressure of 1 atm and a temperature of 300 K. The tube is slowly heated and it is found that the cork pops out when the temperature reaches 600 K. Let dN denote the magnitude of the normal contact force exerted by a small length dlof the cork along the periphery (see the figure). Assuming that the temperature of the gas is uniform at any instant, calculate `(dN)/(dt)`.
The temperature and the dew point in an open room are 20°C and 10°C. If the room temperature drops to 15°C, what will be the new dew point?
Figure shows two rigid vessels A and B, each of volume 200 cm3, containing an ideal gas (Cv = 12.5 J K−1 mol−1). The vessels are connected to a manometer tube containing mercury. The pressure in both the vessels is 75 cm of mercury and the temperature is 300 K. (a) Find the number of moles of the gas in each vessel. (b) 5.0 J of heat is supplied to the gas in vessel A and 10 J to the gas in vessel B. Assuming there's no appreciable transfer of heat from A to B, calculate the difference in the heights of mercury in the two sides of the manometer. Gas constant, R = 8.3 J K−1 mol−1.
Answer in brief:
What will happen to the mean square speed of the molecules of a gas if the temperature of the gas increases?
Energy is emitted from a hole in an electric furnace at the rate of 20 W when the temperature of the furnace is 727°C. What is the area of the hole? (Take Stefan’s constant σ to be 5.7 × 10-8 Js-1 m-2K-4.)
The power radiated by a perfect blackbody depends only on its ______
Calculate the value of λmax for radiation from a body having a surface temperature of 3000 K. (b = 2.897 x 10-3 m K)
On what, the values of absorption coefficient, reflection coefficient, and transmission coefficient depend, in addition to the material of the object on which the radiation is an incident?
Above what temperature, all bodies radiate electromagnetic radiation?
The average translational kinetic energy of gas molecules depends on ____________.
What is the microscopic origin of temperature?
The average K.E. of hydrogen molecules at 27° C is E. The average K.E. at 627° C is ____________.
An ideal gas in a container of volume 500 cc is at a pressure of 2 × 105 N/m2. The average kinetic energy of each molecule is 6 × 10−21 J. The number of gas molecules in the container is ______.
A cylinder containing an ideal gas is in vertical position and has a piston of mass M that is able to move up or down without friction (Figure). If the temperature is increased ______.
Volume versus temperature graphs for a given mass of an ideal gas are shown in figure at two different values of constant pressure. What can be inferred about relation between P1 and P2?
An insulated container containing monoatomic gas of molar mass m is moving with a velocity vo. If the container is suddenly stopped, find the change in temperature.
For a particle moving in vertical circle, the total energy at different positions along the path ______.
When a particle oscillates simple harmonically, its kinetic energy varies periodically. If frequency of the particle is n, then the frequency of the kinetic energy is ______.
According to the kinetic theory of gases, at a given temperature, molecules of all gases have the same ______.
2000 calories of radiant heat is incident on a body. If the body absorbs 550 calories of heat, find the coefficient of emmission of the body.
