Answer
current density is given by
where J = σ E
now,
a) Electric field strength at the inner surface of an iron cylinder
a = 0.5 cm = 0.005 m b = 2.3 = 0.023
L = 10 cm = 0.1 m I = 27 A
E = 8.59 x 10⁻⁴ V/m
b) Electric field strength at the outer surface of an iron cylinder
a = 0.5 cm = 0.005 m b = 2.3 = 0.023
L = 10 cm = 0.1 m I = 27 A
E =1.87 x 10⁻⁴ V/m
Answer:
1.8m
Explanation:
Let the Elastics of the steel ASTM-36
The strain of the bar when subjected to 150 MPa is
Therefore, if the bar elongates by 1.35 mm, then the original length L would be:
or 1.8m
Answer:
14869817.395 m
Explanation:
=22 microarcsecond
λ = Wavelength = 1.3 mm
Converting to radians we get
From Rayleigh Criterion
Diameter of the effective primary objective is 14869817.395 m
It is not possible to build one telescope with a diameter of 14869817.395 m. But, we need this type of telescope. So, astronomers use an array of radio telescopes to achieve a virtual diameter in order to observe objects that are the size of supermassive black hole's event horizon.