Answer:
The near point of an eye with power of +2 dopters, u' = - 50 cm
Given:
Power of a contact lens, P = +2.0 diopters
Solution:
To calculate the near point, we need to find the focal length of the lens which is given by:
Power, P = 
where
f = focal length
Thus
f = 
f =
= + 0.5 m
The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.
Now, by using lens maker formula:

where
u = object distance = 25 cm = 0.25 m = near point of a normal eye
u' = image distance
Now,



Solving the above eqn, we get:
u' = - 0.5 m = - 50 cm
Answer:
The smallest diameter is 
Explanation:
From the question we are told that
The resolution of the telescope is 
The wavelength is 
From the question we are told that

So 
Therefore


Now 
So 
=> 

The smallest diameter is mathematically represented as

substituting values


Answer:
The number of valence electrons increases to 8 or, the atom gives up loosely held valence electrons.
Explanation:
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Answer:
Refraction
Explanation:
When light passes from a rarer medium into a denser medium, it bends in the medium away from the normal. This creates the phenomenon of "apparent depth" as given in the question.
Answer:
λ = 65.6 pm
Explanation:
Given that
λo = 65 pm
The initial energy of the electron

Now by putting the values




Eo=19.06 KeV
Given that kinetic energy KE= 0.84 KeV
Therefore the final energy
E= Eo - KE
E = 19.06 - 0.84 KeV
E= 18.22 KeV
The wavelength λ can be find as



λ = 6.56 x 10⁻¹¹ m
λ = 65.6 pm