Skip to content
Explain how the color of an object is determined and describe the process of color subtraction using the example of a shirt.The color of an object is determined by the specific wavelengths of light it reflects and the ones it absorbs. For example, when white light strikes a shirt that absorbs red light, the red wavelength is subtracted from the white spectrum. The shirt then reflects the remaining green and blue light, which combine to make the shirt appear cyan to our eyes. If yellow light, which consists of red and green, is projected onto this same red-absorbing shirt, the red is subtracted and only green is reflected. Thus, the perceived color depends entirely on the object’s absorption properties and the color of the light illuminating it.
How can the laws of reflection be verified experimentally?To verify the laws of reflection, a white paper is fixed on a drawing board with a plane mirror placed vertically along a drawn line XY. Two pins, P and Q, are fixed in front of the mirror, and two more pins, R and S, are placed such that they align in a straight line with the images of P and Q. After removing the pins, lines are drawn to represent the incident ray, reflected ray, and a normal line perpendicular to the mirror line. Measuring the angles with a protractor reveals that the angle of incidence is always equal to the angle of reflection. Since all the drawn lines and pins are situated on the flat sheet of paper, it also proves that they lie in the same plane.
Differentiate between specular and diffused reflection, and explain why drivers find it difficult to drive on wet roads at night.Specular reflection occurs when parallel rays of light fall on a smooth, highly polished surface like a mirror and reflect as parallel rays in a single direction. In contrast, diffused reflection happens on rough surfaces where surface irregularities reflect parallel incident rays at different angles and in different directions. Under normal night conditions, a dry road surface provides diffused reflection, allowing drivers to see the road clearly from all angles. However, water on a wet road smooths out these surface irregularities, causing the reflection to change from diffused to specular. This specular reflection bounces the headlight beams of oncoming cars directly into the driver’s eyes, creating a highly distracting and dangerous glare.
Describe the characteristics of the image formed by a plane mirror and explain how the image of an extended-sized object is formed.When an extended-sized object is placed in front of a plane mirror, light rays travel from all its points to the mirror and reflect according to the laws of reflection. These reflected rays appear to diverge from corresponding points behind the mirror, forming a virtual image. This formed image is always the exact same size as the original object and is located at an equal distance behind the mirror as the object is in front of it. Additionally, the image exhibits lateral inversion, which means that the right side of the object appears as the left side in its reflection, and vice versa.
Share
Explore
Answer key
Prepared by: learnloophq@gmail.com
Chapter: 04. Light
Want to print your doc?
This is not the way.
This is not the way.
Try clicking the ··· in the right corner or using a keyboard shortcut (
CtrlP
) instead.