-4.0 (negative since the image is inverted)
Answer:
d.The wavelength of light and the size of the aperture
Explanation:
<em>The resolution power of an optical system is the smallest distance between two points that the device can distinguish clearly.</em>
It has the following relationship:

where:
r = minimum resolvable distance
n = numerical aperture
= wavelength of the light used for viewing
From above mathematical equation it is clear that:
- Smaller the wavelength better the resolving power
- Larger the aperture better the resolution
(Note, that smaller the value of "r" the more finer details of the image visible through the device.)
Answer: 2000 J.
Explanation: Since work is force*displacement, we just have to multiply the force by the distance: w = f*d = 400 N*5.0 m = 2000 J.

Every object in the universe attracts every other object with a force which is proportional to the product of their masses and inversely proportional to the square of the distance between them. The forces along the line joining the centre of the two objects.
❍ Let us consider two masses m1 and m2 line at a separation distance d. Let the force of attraction between the two objects be F.
According to universal law of gravitation,

Also,

Combining both, We will get

Or, We can write it as,

Where, G is the constant of proportionality and it is called 'Universal Gravitational constant'.
☯️ Hence, derived !!
<u>━━━━━━━━━━━━━━━━━━━━</u>