The Human Eye Quiz

The cornea is a thin membrane that allows light to enter the eye and is responsible for most of the refraction of light.

The iris adjusts the size of the pupil to regulate the amount of light entering the eye; it contracts in bright light and expands in dim light.

The crystalline lens provides a focused, real, and inverted image of objects on the retina and is made of a jelly-like substance.

<p>The retina contains light-sensitive cells that activate and generate electrical signals when an image is formed.</p> Signup and view all the answers

<p>Ciliary muscles change the curvature of the lens, altering its focal length to enable clear vision of objects at different distances.</p> Signup and view all the answers

<p>Persistence of vision is the duration for which the sensation of an object continues in the eye, lasting about 1/16th of a second.</p> Signup and view all the answers

<p>The pupil is constricted in low light, and it takes time for the iris to expand the pupil to allow more light in.</p> Signup and view all the answers

<p>In dim light, the iris relaxes, causing the pupil to expand so that more light can enter the eye.</p> Signup and view all the answers

<p>Hypermetropia is corrected using a convex lens, which converges light rays to focus them on the retina, compensating for the eye's inability to focus on nearby objects.</p> Signup and view all the answers

<p>Presbyopia is the gradual loss of the eye's ability to focus on close objects, primarily due to weakened ciliary muscles and decreased lens flexibility.</p> Signup and view all the answers

<p>A prism has two triangular bases and three rectangular lateral surfaces, bending light through different angles, creating an angle of deviation between the incident and emergent rays.</p> Signup and view all the answers

<p>The angle of deviation is the angle formed between the incident ray and the emergent ray as light passes through the prism.</p> Signup and view all the answers

<p>Bifocal lenses contain both concave and convex lenses; the upper part corrects distance vision (concave), while the lower part helps with near vision (convex).</p> Signup and view all the answers

<p>The process is called Dispersion.</p> Signup and view all the answers

<p>Red light bends the least.</p> Signup and view all the answers

<p>Newton concluded that sunlight is made up of seven visible colors known as VIBGYOR.</p> Signup and view all the answers

<p>A rainbow is formed when sunlight is dispersed by tiny water droplets, acting like prisms, reflecting internally and then refracting when emerging.</p> Signup and view all the answers

<p>The second prism allows all colors of the spectrum to pass through, resulting in white light emerging on the other side.</p> Signup and view all the answers

<p>VIBGYOR stands for Violet, Indigo, Blue, Green, Yellow, Orange, and Red.</p> Signup and view all the answers

<p>Different colors of light bend at different angles due to variations in their wavelengths.</p> Signup and view all the answers

<p>The inclined refracting surfaces cause the white light to split into its component colors.</p> Signup and view all the answers

<p>A rainbow forms due to the refraction, dispersion, and internal reflection of light in raindrops, with red at the top and violet at the bottom.</p> Signup and view all the answers

<p>Atmospheric refraction causes stars to appear higher than their actual position because their light bends towards the normal as it passes through varying layers of atmospheric density.</p> Signup and view all the answers

<p>Star twinkling is caused by atmospheric refraction, which changes the apparent position of the star and causes fluctuations in brightness as light enters the atmosphere.</p> Signup and view all the answers

<p>Planets do not twinkle because they are closer to Earth and are perceived as extended sources of light rather than point sources.</p> Signup and view all the answers

<p>At point A, sunlight undergoes refraction and dispersion as it enters a raindrop, leading to the separation of colors.</p> Signup and view all the answers

<p>At point B, internal reflection occurs within the raindrop, causing the light to bounce back towards the observer.</p> Signup and view all the answers

<p>At point C, refraction and dispersion occur again as the light exits the raindrop, forming a complete rainbow.</p> Signup and view all the answers

<p>Varying atmospheric density causes the light from distant stars to refract differently, altering their apparent position in the sky.</p> Signup and view all the answers

<p>Twinkling of stars is caused by atmospheric refraction, which varies the amount of light entering our eyes from the point-sized sources of light.</p> Signup and view all the answers

<p>We can see the sun about 2 minutes earlier than sunrise and about 2 minutes after sunset.</p> Signup and view all the answers

<p>The Tyndall Effect is the scattering of light by colloidal particles, observed when sunlight passes through a dense forest canopy.</p> Signup and view all the answers

<p>Clouds appear white because the size of the water droplets scatters all wavelengths of light almost equally.</p> Signup and view all the answers

<p>The blue color of the sky is due to Rayleigh scattering, where smaller particles scatter shorter wavelengths of light more effectively.</p> Signup and view all the answers

<p>Very fine particles scatter short wavelengths (blue), while larger particles scatter longer wavelengths (red).</p> Signup and view all the answers

<p>Without Earth's atmosphere, there would be no scattering, and the sky would appear dark.</p> Signup and view all the answers

<p>Rayleigh scattering is given by the formula $S \propto \frac{1}{\lambda^4}$, indicating that scattering decreases with increasing wavelength.</p> Signup and view all the answers