Advertisements
Advertisements
प्रश्न
The light from the Sun is found to have a maximum intensity near the wavelength of 470 nm. Assuming the surface of the Sun as a black body, the temperature of the Sun is _____________.
[Wien's constant b = 2 .898 x l0- 3mK]
पर्याय
5800 K
6050 K
6166 K
6500 K
Advertisements
उत्तर
The light from the Sun is found to have a maximum intensity near the wavelength of 470 nm. Assuming the surface of the Sun as a black body, the temperature of the Sun is 6166 K.
Explanation:
Given: λm= 470nm = 4.70×10−7m b = 2.898×10−3mK
From Wien's displacement law,
Tλm = b
We get, temperature of sun
T = `b/(λ_m)`
∴ T = `(2.898 xx 10^(−3))/(4.70 xx 10^(−7))` = 6166 K
APPEARS IN
संबंधित प्रश्न
Two copper spheres of radii 6 cm and 12 cm respectively are suspended in an evacuated enclosure. Each of them are at a temperature 15°C above the surroundings. The ratio of their rate of loss of heat is.................
- 2:1
- 1:4
- 1:8
- 8:1
A pinhole is made in a hollow sphere of radius 5 cm whose inner wall is at temperature 727oC. Find the power radiated per unit area. [Stefan’s constant σ = 5.7 x 10-8 J/m2 s K4 , emissivity (e) = 0.2]
Compute the temperature at which the r.m.s. speed of nitrogen molecules is 832 m/s. [Universal gas constant, R = 8320 J/k mole K, molecular weight of nitrogen = 28.]
A metal ball cools from 64 °C to 50 °C in 10 minutes and to 42 °C in next 10 minutes. The ratio of rates of fall of temperature during the two intervals is _______.
Answer the following:
There were two fixed points in the original Celsius scale as mentioned above which were assigned the number 0 °C and 100 °C respectively. On the absolute scale, one of the fixed points is the triple-point of water, which on the Kelvin absolute scale is assigned the number 273.16 K. What is the other fixed point on this (Kelvin) scale?
A body cools from 62°C to 54°C in 10 minutes and to 48°C in the next 10 minutes. Find the temperature of the surroundings.
It is said that mercury is used in defining the temperature scale because it expands uniformly with temperature. If the temperature scale is not yet defined, is it logical to say that a substance expands uniformly with temperature?
Which of the curves in the following figure represents the relation between Celsius and Fahrenheit temperatures?

The temperature of water at the surface of a deep lake is 2°C. The temperature expected at the bottom is
The atmospheric temperature in the cities on sea-coast change very little. Explain
Water equivalent of a body is measured in ___________ .
The mechanical equivalent of heat ____________ .
The heat capacity of a body depends on
(a) the heat given
(b) the temperature raised
(c) the mass of the body
(d) the material of the body
The temperature of a solid object is observed to be constant during a period. In this period
(a) heat may have been supplied to the body
(b) heat may have been extracted from the body
(c) no heat is supplied to the body
(d) no heat is extracted from the body
A resistance thermometer reads R = 20.0 Ω, 27.5 Ω, and 50.0 Ω at the ice point (0°C), the steam point (100°C) and the zinc point (420°C), respectively. Assuming that the resistance varies with temperature as Rθ = R0 (1 + αθ + βθ2), find the values of R0, α and β. Here θ represents the temperature on the Celsius scale.
A concrete slab has a length of 10 m on a winter night when the temperature is 0°C. Find the length of the slab on a summer day when the temperature is 35°C. The coefficient of linear expansion of concrete is 1.0 × 10–5 °C–1.
A metre scale made of steel is calibrated at 20°C to give correct reading. Find the distance between the 50 cm mark and the 51 cm mark if the scale is used at 10°C. Coefficient of linear expansion of steel is 1.1 × 10–5 °C–1.
A pendulum clock shows correct time at 20°C at a place where g = 9.800 m s–2. The pendulum consists of a light steel rod connected to a heavy ball. It is taken to a different place where g = 9.788 m s–1. At what temperature will the clock show correct time? Coefficient of linear expansion of steel = 12 × 10–6 °C–1.
A steel rod of length 1 m rests on a smooth horizontal base. If it is heated from 0°C to 100°C, what is the longitudinal strain developed?
Answer the following question.
Clearly, state the difference between heat and temperature?
Define one mole.
Temperature and Heat are ______
Our normal body temperature is ______.
Two tumblers of A and B have water at 50°C temperature. If the water from A and B is poured into tumbler C. The temperature of C is ______.
One day in 1922, the air temperature was measured at 59°C in the shade in Libya ______.
The degree of hotness and coldness of a body is called ______.
The temperature of a liquid drops from 365 K to 361 K in 2 min. Find the time during which the temperature of the liquid drops from 344 K to 342 K.
(Take, room temperature = 293 K)
What condition defines thermal equilibrium between two bodies?
