Mix Examples - The Human Eye and the Colourful World Questions in English

(N/A) Ciliary muscles help in changing the focal length of the eye lens.
$(b)$ Cataract: The crystalline lens of the eye is made of proteins arranged in a regular pattern,which makes the lens transparent. When a group of these protein molecules clump together in a region,they make the region opaque. Gradually,this membrane grows,and the whole lens becomes opaque.
$(c)$ The colour of scattered light depends on the size of the scattering particles (air molecules,dust particles,and pollutants) in the atmosphere.
$(d)$ From $25 \ cm$ to infinity.
$(e)$ There is no atmosphere in space,hence there are no air molecules to scatter sunlight,making the sky appear dark.

(N/A) Hypermetropia,also known as farsightedness,is a vision defect where a person can see distant objects clearly but cannot see nearby objects distinctly. This happens because the near point of the eye has shifted further away than the normal $25 \ cm$.
Reasons for hypermetropia:
$1$. The eyeball has become too short.
$2$. The focal length of the eye lens has become too large.
Correction: This defect is corrected by using a convex lens of suitable focal length,which converges the light rays before they enter the eye,allowing the image to form on the retina.
$(b)$ The experimental arrangement for observing the Tyndall effect (scattering of light) involves passing a strong beam of light through a colloidal solution (e.g.,sodium thiosulphate solution). The two chemicals used are:
$1$. Sodium thiosulphate $(Na_2S_2O_3)$
$2$. Concentrated sulphuric acid $(H_2SO_4)$

(A) In a compound microscope,the objective lens forms a real,inverted,and enlarged image of the object.
This image acts as an object for the eyepiece (ocular lens).
The eyepiece acts as a simple magnifier and forms a virtual,erect (with respect to the intermediate image),and further enlarged image.
Since the intermediate image was inverted,the final image appears inverted with respect to the original object.
Therefore,the final image formed by a compound microscope is virtual,inverted,and enlarged compared to the original object.

(A) In an astronomical telescope,the objective lens is designed to collect as much light as possible from distant objects,which requires a large aperture and a large focal length $(f_o)$.
Conversely,the eyepiece is used as a magnifying glass to view the image formed by the objective lens,which requires a short focal length $(f_e)$.
Therefore,for high magnification $(M = -f_o / f_e)$,the focal length of the objective lens is much larger than the focal length of the eyepiece $(f_o > f_e)$.

(D) In the context of light and color vision,the primary colors are Red,Green,and Blue $(RGB)$.
These colors are considered primary because they cannot be created by mixing other colors,and they can be combined in various intensities to produce a wide spectrum of other colors.
Therefore,the correct option is $D$.

(C) The primary colours of light are $Red$,$Green$,and $Blue$ $(RGB)$.
These colours are considered primary because they cannot be created by mixing other colours of light,but when combined in various intensities,they can produce a wide range of colours,including white light.

(A) The process of creating a wide range of colors by combining primary colors (such as Red, Green, and Blue) in different proportions is known as $Additive$ $\text{color mixing}$.
In this method, light of different wavelengths is added together to produce new colors.
For example, mixing Red and Green light produces Yellow light.
Therefore, the correct option is $A$.

(C) The colors obtained by mixing primary colors (such as Red,Green,and Blue in the context of light) are known as secondary colors.
When primary colors are combined in different proportions,they produce a wide range of secondary colors.
For example,mixing Red and Green light produces Yellow,Green and Blue produces Cyan,and Red and Blue produces Magenta.

(D) In the context of additive color mixing (light),the primary colors are $Red$,$Green$,and $Blue$ $(RGB)$.
These colors are considered primary because they cannot be created by mixing other colors,and they can be combined in various intensities to produce a wide range of other colors.
$Yellow$ is a secondary color formed by mixing $Red$ and $Green$ light.
Therefore,$Yellow$ is not a primary color.

(B) The color maroon is a dark shade of red. In the context of additive color mixing (light),maroon is produced by combining red light with a smaller proportion of blue light. Therefore,the combination of red and blue light results in the formation of maroon.

(A) According to the additive color mixing theory of light,the primary colors of light are Red,Green,and Blue $(RGB)$.
When red light and green light are mixed or overlap,they produce yellow light.
Therefore,the region where red and green light overlap appears yellow.

(B) The color known as peacock blue or cyan is a secondary color formed by the additive mixing of two primary colors of light: blue and green. In the context of light,the superposition of blue and green light waves results in the perception of peacock blue.

(A) In the additive color mixing model ($RGB$ model),light colors combine to form new colors. When red light and green light are mixed together,they produce yellow light. This is a fundamental principle of light addition.

(D) When light of the three primary colors—red,green,and blue—overlap in equal intensity,they combine to form white light. This is a fundamental principle of additive color mixing in physics.

(D) When two colors of light are mixed to produce white light,they are known as complementary colors. Examples include blue and yellow light,or red and cyan light. These pairs are called complementary because they complete the spectrum required to perceive white light.

(D) When blue and yellow light are superimposed,they are complementary colors in the context of additive color mixing. The combination of blue and yellow light results in white light. This is a fundamental principle in color theory where specific pairs of colors,when combined,produce white light.

(B) The primary colors of light are Red,Green,and Blue $(RGB)$.
These colors are considered primary because they cannot be created by mixing other colors of light,and they can be combined in various intensities to produce a wide range of colors.
Yellow,Cyan,and Magenta are secondary colors of light.
Maroon is a dark brownish-red color and is not a primary color of light.

(B) The process of mixing pigments to create different colors is known as $Subtractive$ $mixing$.
In this method,pigments absorb (subtract) specific wavelengths of light from white light,reflecting only the remaining colors to our eyes.
This is the principle used in painting,printing,and color photography.