| #3551 |
What are the types of electric charge? |
Positive and Negative |
| #3552 |
What is electric charge? |
Property of matter that causes it to experience force in an electric field, measured in Coulombs (C) |
| #3553 |
How is chromatic aberration minimized? |
Using combination of convex and concave lenses (achromatic doublet) |
| #3554 |
What is chromatic aberration? |
Dispersion of colors causing blurred image in lenses |
| #3555 |
What is the role of lenses in correcting vision? |
They adjust the focal point of light on the retina |
| #3556 |
What is the principle behind optical fibers? |
Total internal reflection of light within a core with higher refractive index |
| #3557 |
What is the focal length of a lens or mirror? |
Distance between the optical center and the focus, where parallel rays converge |
| #3558 |
How does a telescope form a magnified image? |
Objective lens forms real image, eyepiece lens magnifies it for observation |
| #3559 |
How does a compound microscope form a magnified image? |
Image formed by objective lens acts as object for eyepiece lens, producing a virtual, enlarged image |
| #3560 |
What is a telescope? |
Instrument to observe distant objects, can be refracting (lenses) or reflecting (mirrors) |
| #3561 |
What is a microscope? |
Optical instrument to view small objects, uses combination of objective and eyepiece lenses |
| #3562 |
How are vision defects corrected? |
Myopia: concave lens; Hypermetropia: convex lens; Astigmatism: cylindrical lens; Presbyopia: bifocal lens |
| #3563 |
What are common defects of vision? |
Myopia (nearsightedness), Hypermetropia (farsightedness), Presbyopia, Astigmatism, Cataract |
| #3564 |
What is the human eye’s structure? |
Cornea, lens, iris, retina, optic nerve |
| #3565 |
Why does the sun appear red at sunrise and sunset? |
Longer path through atmosphere scatters blue light, leaving red light |
| #3566 |
Why is the sky blue? |
Due to Rayleigh scattering, shorter wavelengths (blue) scatter more than longer wavelengths |
| #3567 |
What is scattering of light? |
Deviation of light by particles in the atmosphere, causing sky color and reddish sunsets |
| #3568 |
How is a rainbow formed? |
By refraction, reflection, and dispersion of sunlight in raindrops |
| #3569 |
What is dispersion of light? |
Separation of white light into constituent colors due to different refractive indices |
| #3570 |
What is magnification? |
Ratio of image height to object height, $M = h’/h = v/u$ |
| #3571 |
What is the lens formula? |
$1/f = 1/v – 1/u$ |
| #3572 |
What are concave and convex lenses? |
Convex lens converges light; Concave lens diverges light |
| #3573 |
What is the mirror formula? |
$1/f = 1/v + 1/u$, where f is focal length, v is image distance, u is object distance |
| #3574 |
What are concave and convex mirrors? |
Concave: curved inward; Convex: curved outward |
| #3575 |
Name some applications of TIR. |
Optical fibers, periscopes, binoculars, prisms in cameras |