Every question from this NCERT chapter, with a detailed explanation.
In the context of the reflection of light, what does the term 'angle of incidence' refer to?
With reference to image formation by a plane mirror, consider the following statements: 1. The image formed cannot be obtained on a screen. 2. The image appears at a greater distance behind the mirror than the object is in front. 3. The image undergoes lateral inversion. Which of the statements given above are correct?
Which one of the following terms describes the phenomenon where the left of an object appears on the right in a mirror image?
With reference to reflection from different surfaces, consider the following statements: 1. Regular reflection occurs when parallel rays fall on an irregular surface. 2. Diffused reflection occurs when parallel rays fall on an irregular surface and are reflected in different directions. 3. Diffused reflection is caused by irregularities in the reflecting surface. Which of the statements given above is/are correct?
What is the primary optical mechanism that enables the visibility of non-luminous objects?
Consider the following statements distinguishing Luminous and Illuminated objects: 1. The Sun and a candle flame are examples of illuminated objects. 2. The Moon is an example of an illuminated object. 3. Illuminated objects emit their own light. Which of the statements given above is/are correct?
What type of reflection occurs when parallel rays of light strike an irregular surface such as cardboard?
With reference to the Periscope, consider the following statements: 1. It works on the principle of multiple reflections. 2. It uses two plane mirrors arranged at right angles to each other. 3. It allows viewing of objects that are not directly in the line of sight. Which of the statements given above are correct?
Consider the following statements regarding images formed by two plane mirrors: 1. If two mirrors are placed parallel to each other, a finite number of images are formed. 2. If two mirrors are placed at right angles, multiple images are formed. 3. The number of images depends on the angle between the mirrors. Which of the statements given above is/are correct?
Which one of the following optical instruments utilizes the principle of multiple reflections to create symmetrical patterns?
With reference to the construction of a Kaleidoscope, consider the following statements: 1. It typically uses three rectangular mirror strips joined to form a prism. 2. One end of the tube is closed by a completely opaque metal plate. 3. The patterns formed are fixed and repeat exactly every time the tube is rotated. Which of the statements given above is/are correct?
What is the optical principle applied when a hairdresser holds a mirror behind a customer to show the back of the head?
Consider the following statements regarding light: 1. Sunlight is referred to as white light. 2. Splitting of light into its constituent colours is known as lateral inversion. 3. A rainbow is a natural phenomenon showing dispersion. Which of the statements given above is/are correct?
With reference to the human eye, consider the following statements: 1. The cornea gives the eye its distinctive colour. 2. The pupil appears dark because no light is reflected from it. 3. In bright light, the iris contracts the pupil to allow less light in. Which of the statements given above is/are correct?
In the human optical system, which structure functions as the light-sensitive screen upon which images are projected?
Consider the following statements about the nerve cells found in the retina: 1. Cones are sensitive to bright light. 2. Rods are sensitive to bright light only. 3. Rods are responsible for sensing colour. Which of the statements given above is/are correct?
With reference to the anatomy of the human eye, what characterizes the region known as the 'blind spot'?
With reference to the functioning of the eye lens, consider the following statements: 1. It is a convex lens, thicker in the centre. 2. It focuses light exactly on the optic nerve. 3. It becomes cloudy in the case of a cataract. Which of the statements given above is/are correct?
The phenomenon of 'persistence of vision' relies on the fact that an image remains on the retina for a specific duration after the object is removed. This duration is approximately:
The illusion of continuous movement in cinematography is primarily achieved through which of the following mechanisms?
With reference to eye defects, consider the following statements: 1. Near-sighted persons cannot see nearby objects clearly. 2. Far-sighted persons cannot see nearby objects clearly. 3. Cataract can be treated by replacing the opaque lens with an artificial one. Which of the statements given above are correct?
Deficiency of which one of the following nutrients is the primary cause of the condition known as 'Nyctalopia' or night blindness?
Consider the following food items: 1. Raw carrots 2. Spinach 3. Cod liver oil 4. Eggs Which of the above are rich sources of Vitamin A beneficial for eyes?
With reference to the eyes of animals, consider the following statements: 1. Crabs have large eyes that allow them to look only in the front. 2. Butterflies have large eyes composed of thousands of little eyes. 3. Owls have a small cornea and pupil to restrict light entry. Which of the statements given above are correct?
Which of the following anatomical features primarily enables nocturnal birds, such as owls, to see effectively in low-light conditions?
With reference to visual adaptation, how does the retinal composition of a diurnal bird (e.g., eagle) differ from that of a nocturnal bird (e.g., owl)?
Consider the following statements regarding the Braille system: 1. It was developed by Louis Braille in 1821. 2. The system uses 108 dot patterns or characters. 3. Each character represents a letter, a combination of letters, a common word, or a grammatical sign. Which of the statements given above are correct?
In the standard Braille system used by the visually impaired, the fundamental cell structure consists of:
Consider the following statements about the image formed by a plane mirror: 1. It is inverted vertically. 2. It is of the same size as the object. 3. It appears to be at the same distance behind the mirror as the object is in front. Which of the statements given above is/are correct?
In an experiment demonstrating the laws of reflection, if the plane containing the reflected ray is disrupted (e.g., by bending the paper), the ray becomes invisible. This validates which principle?
Consider the following statements regarding 'Diffused Reflection': 1. It occurs on smooth surfaces like mirrors. 2. The reflected rays are not parallel to each other. 3. It prevents us from seeing non-luminous objects. Which of the statements given above are correct?
Which one of the following celestial or terrestrial bodies does not emit its own light?
The working principle of a kaleidoscope involves the arrangement of mirrors to produce which of the following optical effects?
Consider the following statements about the human eye: 1. The outer coat of the eye is white and tough. 2. The ciliary muscle controls the movement of the eyelids. 3. The optic nerve transmits sensations to the brain. Which of the statements given above is/are correct?
In the human visual system, what is the primary protective function of the eyelids?
For a normal human eye, the 'least distance of distinct vision', representing the minimum distance at which objects can be seen clearly without strain, is approximately:
With reference to the anatomy of the human eye, which statement correctly describes the 'blind spot'?
Consider the following statements regarding the care of eyes: 1. Too little light improves visual acuity. 2. Looking directly at the Sun can injure the retina. 3. One should wash eyes with clean water if dust enters them. Which of the statements given above is/are correct?
In the context of assistive technologies for the visually impaired, which one of the following is classified as a 'Non-optical aid'?
Consider the following statements about the reflection of light: 1. A mirror changes the direction of light that falls on it. 2. A polished surface absorbs all light falling on it. 3. Light travels in curved lines when reflected. Which of the statements given above is/are correct?
The formation of a rainbow is primarily a result of which of the following optical phenomena?
Which component of the human eye regulates the amount of light entering by adjusting the size of the pupil?
Consider the following statements regarding the image formed by a plane mirror: 1. The image is virtual. 2. The image is formed on the surface of the mirror. 3. The image is laterally inverted. Which of the statements given above is/are correct?
In the context of human vision, what is the primary function of the photoreceptor cells known as 'cones'?
Consider the following statements about the 'Periscope': 1. It is primarily used in aircraft for navigation. 2. It allows soldiers in bunkers to see things outside. 3. It uses plane mirrors to reflect light. Which of the statements given above is/are correct?
When a person moves from a dimly lit environment to a brightly lit environment, how does the pupil of the eye adapt?
In the context of the laws of reflection, the term 'Normal' refers to:
Consider the following statements regarding 'Cataract': 1. It occurs exclusively in children. 2. It is caused by the eye lens becoming cloudy. 3. It cannot be treated. Which of the statements given above is/are correct?
With reference to the Braille system, consider the following statements: 1. It is a resource for visually challenged persons. 2. The dots are depressed to allow recognition by touch. 3. Visually impaired people learn it by beginning with letters. Which of the statements given above is/are correct?
Consider the following statements regarding the 'Kaleidoscope': 1. It works on the principle of refraction. 2. It is used by designers of wallpapers and fabrics for new pattern ideas. 3. It consists of three rectangular mirror strips. Which of the statements given above is/are correct?
Which one of the following anatomical structures is NOT a component of the human visual system?
If a ray of light strikes a plane mirror along the normal to the surface, what is the resulting angle of reflection?
Consider the following statements about 'Regular Reflection': 1. It takes place from a smooth surface. 2. Images cannot be formed by regular reflection. 3. It occurs when parallel rays are reflected in different directions. Which of the statements given above is/are correct?
What is the primary function of the optic nerve in the human visual system?
With reference to the eye's ability to see, consider the following statements: 1. A normal eye can clearly see distant objects as well as objects nearby. 2. The minimum distance for distinct vision is constant at 50 cm for all ages. 3. In old age, eyesight may become foggy due to the eye lens becoming cloudy. Which of the statements given above is/are correct?
Consider the following statements regarding 'Dispersion of Light': 1. It is the combining of colours to form white light. 2. A prism can be used to demonstrate dispersion. 3. Sunlight consists of seven colours. Which of the statements given above are correct?
The retina of the human eye contains which types of photoreceptor cells?
Which statement correctly describes the structure or function of the iris in the human eye?
With reference to the 'Blind Spot', consider the following statements: 1. It is located at the center of the cornea. 2. It has no sensory cells. 3. An image formed here is sent to the brain very slowly. Which of the statements given above is/are correct?