Answer:
The correct answer is B
Explanation:
Let's calculate the electric field using Gauss's law, which states that the electric field flow is equal to the charge faced by the dielectric permittivity
Φ
= ∫ E. dA =
/ ε₀
For this case we create a Gaussian surface that is a sphere. We can see that the two of the sphere and the field lines from the spherical shell grant in the direction whereby the scalar product is reduced to the ordinary product
∫ E dA =
/ ε₀
The area of a sphere is
A = 4π r²
E 4π r² =
/ ε₀
E = (1 /4πε₀
) q / r²
Having the solution of the problem let's analyze the points:
A ) r = 3R / 4 = 0.75 R.
In this case there is no charge inside the Gaussian surface therefore the electric field is zero
E = 0
B) r = 5R / 4 = 1.25R
In this case the entire charge is inside the Gaussian surface, the field is
E = (1 /4πε₀
) Q / (1.25R)²
E = (1 /4πε₀
) Q / R2 1 / 1.56²
E₀ = (1 /4π ε₀
) Q / R²
= Eo /1.56
²
= 0.41 Eo
C) r = 2R
All charge inside is inside the Gaussian surface
=(1 /4π ε₀
) Q 1/(2R)²
= (1 /4π ε₀
) q/R² 1/4
= Eo 1/4
= 0.25 Eo
D) False the field changes with distance
The correct answer is B
Answer:
Explanation:
The problem is based on interference in thin films
refractive index of water is more than given oil so there will be phase change of π at upper and lower layer of the film .
a )
for constructive interference , the condition is
2μt = nλ where t is thickness of layer , μ is refractive index , λ is wavelength and n is order of the fringe
Putting the values
2 x 1.27 t = n x 640
2 x 1.27 t = 640 ( for minimum thickness n = 1 )
t = 252 nm .
b )
2 x 1.27 t = m₁ λ₁
for destructive interference
2μt = (2m₂+1)λ₂/2
2 x 1.27 t =(2m₂+1)λ₂/2
m₁ λ₁ = (2m₂+1)λ₂/2
2m₁λ₁ = (2m₂+1)λ₂
2m₁ / (2m₂+1) = λ₂ / λ₁
2m₁ / (2m₂+1) = 548/ 640
2m₁ / (2m₂+1) = .85625
2m₁ = .85625 (2m₂+1)
This is the required relation between m₁ and m₂
B would be your right answer. Because Jupiter’s gravity pull is much stronger than earths