To solve this problem we will apply the concepts related to the intensity included as the power transferred per unit area, where the area is the perpendicular plane in the direction of energy propagation.
Since the propagation occurs in an area of spherical figure we will have to


Replacing with the given power of the Bulb of 100W and the radius of 2.5m we have that


The relation between intensity I and 

Here,
= Permeability constant
c = Speed of light
Rearranging for the Maximum Energy and substituting we have then,




Finally the maximum magnetic field is given as the change in the Energy per light speed, that is,



Therefore the maximum value of the magnetic field is 
C. unbalanced is the correct answer for newton's first law.
Answer:

Explanation:
Refractive Index: It is a measure to find how fast the light travels through a medium. It is ration of the speed of light in vacuum to speed of light in the medium. Speed of light is not constant and varies depending on the density of the medium.
In vacuum the speed of light is 300000 km/s and is denoted by c. When the light beam enters any medium the speed will decrease. Here it is given that the speed in plastic is v. Thus the refractive index(n) is given as:

It is a dimensionless no.
The image of the object is 8cm to the left of the lens (D)
<h3>
</h3>
What is the image of an object?
The image of an object is said to be the location where light rays from that object intersect with a mirror by reflection.
It is calculated thus:
1÷v = 1÷f - 1÷u
<h3>How to calculate the image of an object</h3>
From the formula
1÷v = 1÷f - 1÷u
<h3>
Where </h3>
V = image distance fromthe object
U = object
f = focal length
Substitute the values
1÷v = 1÷8 - 1÷ 4
1÷v = - 1÷8
Make v the subject of formula
v = -8cm
Therefore, the image of the object is 8cm to the left of the lens (D)
Learn more on focal length here:
brainly.com/question/25779311
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