To solve this problem it is necessary to apply the concepts related to the Stefan-Boltzmann law which establishes that a black body emits thermal radiation with a total hemispheric emissive power (W / m²) proportional to the fourth power of its temperature.
Heat flow is obtained as follows:
Where,
F =View Factor
A = Cross sectional Area
Stefan-Boltzmann constant
T= Temperature
Our values are given as
D = 0.6m
The view factor between two coaxial parallel disks would be
Then the view factor between base to top surface of the cylinder becomes 
. From the summation rule
Then the net rate of radiation heat transfer from the disks to the environment is calculated as
Therefore the rate heat radiation is 780.76W
Answer:
1371.4watt
Explanation:
from power=energy/time
BUT energy=force times distance
Answer:
c)is unique to that element
Explanation:
The spectrum emitted by a element shows the internal electronic structure of that element.We know that all element is having different internal electronic structure that is why all element emits different spectrum.And the spacing between the spectrum is uneven .
Therefore the answer will be option C.
c)is unique to that element
Mechanical wave shows dual nature
<span>The correct answer is option B. i.e.invention of the microscope. Galileo Galilei invented the microscope and showed its use. Sir Issac Newton invented some part of the calculus, Also invented Newton's Laws of motion and the universal gravitation theory.</span>
