Answer and Explanation:
Every lens have two focal points each focal point is present on the either side of the lens. In lenses when light comes from the infinite it passes through the focal point it is true for both converging as well as diverging lens. In mirror there is only one focal point as it one face is covered but in lens light can pass through side of the lens so it has two focal point
The illumination of the book is found to be approximately equal to 15 lx.
Option 1.
Explanation:
Luminous flux is the measure of power of the light emitted from a source and illumination is the property of the light to illuminate a given surface when it falls on the surface. So the measure of the region the light flux illuminates the surface is termed as illumination.
As here the luminous flux is given as 1759 lm and the distance of the object which has to be illuminated is placed 3 m away from the source ,the illumination is found to be directly proportional to the luminous flux and inversely proportional to the square of the distance between them
So, the illumination of the book is found to be approximately equal to 15 lx.
Answer:
A) d_o = 20.7 cm
B) h_i = 1.014 m
Explanation:
A) To solve this, we will use the lens equation formula;
1/f = 1/d_o + 1/d_i
Where;
f is focal Length = 20 cm = 0.2
d_o is object distance
d_i is image distance = 6m
1/0.2 = 1/d_o + 1/6
1/d_o = 1/0.2 - 1/6
1/d_o = 4.8333
d_o = 1/4.8333
d_o = 0.207 m
d_o = 20.7 cm
B) to solve this, we will use the magnification equation;
M = h_i/h_o = d_i/d_o
Where;
h_o = 3.5 cm = 0.035 m
d_i = 6 m
d_o = 20.7 cm = 0.207 m
Thus;
h_i = (6/0.207) × 0.035
h_i = 1.014 m
When a star collapses to form a black hole,
its mass increases, that is letter C. One example of this is the Big Bang
Theory.
<span>
It is by no doubt that our universe had had its own
starting point but how it really started became a debate for the scientists
over the past centuries. From theories such as Ekpyrotic theory, White Holes,
Matrix theory, and Quantum theory, the Big Bang theory is the theory mostly
accepted by scientists. According to the theory, the universe started as a
singularity, that is, from a black hole under extreme gravitational pressure
and expanded (instead of exploded) and cooled. Its cooling, according to the
theory, is still happening now as of the moment.</span>
