Skip to content
CNMS ICSE - 7 Std
Share
Explore

Answer in one line

Prepared by: learnloophq@gmail.com

Chapter: 04. Light

⁠
What is a translucent object?
A translucent object is a material that lets only some light pass through it while reflecting the remaining portion.
What are the two broad types of mirrors?
Mirrors are broadly classified into plane mirrors and spherical mirrors.
Define the reflected ray.
The reflected ray is the ray of light that bounces back into the same medium after striking a reflecting surface.
Define the angle of reflection.
The angle of reflection is the angle formed between the reflected ray and the normal at the point of incidence.
State the first law of reflection.
The first law of reflection states that the incident ray, the reflected ray, and the normal at the point of incidence all lie in the same plane.
What is lateral inversion?
Lateral inversion is the phenomenon where the right side of" an object appears as the left side in its reflected image, and vice versa.
Why is the word “”“AMBULANCE” written as “3DHAJU8MA” on ambulance vans?
It is written" in a laterally inverted format so that drivers in front can read the word correctly when looking through their rear-view mirrors.
State three characteristics of an image formed by a plane mirror.
The image formed by a plane mirror is of the same size as the object, is laterally inverted, and is situated at the same distance behind the mirror as the object is in front of it.
Give three common uses of plane mirrors.
Plane mirrors are commonly used as looking glasses, in barber shops, and in solar cookers or solar geysers.
What is a kaleidoscope used for?
A kaleidoscope is an optical instrument containing mirrors used for producing colourful, symmetrical patterns.
What is the exact value of the speed of light in a vacuum?
The speed of light in a vacuum is 29,97,92,458 metres per second.
What does Albert Einstein’s theory of special relativity state regarding the speed of light?
The theory of special relativity states that the speed of light is the maximum speed at which all matter in the universe can travel.
What is the speed of light in water?
The speed of light in water is 2.25 × 10⁸ m/s.
What are primary colours of light?
Primary colours are those that cannot be obtained by mixing any other colours but can produce different colours when mixed together.
What are secondary colours of light?
Secondary colours, also known as composite colours, are colours produced by mixing any two primary colours of light.
What colour is produced when all three primary colours of light are mixed together?
When all three primary colours of light are mixed together, they produce white light.
Which two primary colours are mixed to form cyan?
Cyan is formed by mixing blue and green lights together.
Which two primary colours are mixed to form magenta?
Magenta is formed by mixing red and blue lights together.
Why does a blue object appear blue when white light falls on it?
A blue object appears blue because it absorbs all other colours of white light and reflects only the blue light.
Why does a piece of white paper appear red when only red light is thrown on it?
The white paper appears red because it reflects all colours of light falling on it, and only red light is available to be reflected.
How is a rainbow formed in nature?
A rainbow is formed when white sunlight passes through tiny water droplets in the atmosphere, which split the light into its seven constituent colours.
What color will a shirt that absorbs red light appear when yellow light is thrown on it?
The shirt will appear green because yellow light is composed of red and green, and subtracting red leaves only green light to be reflected.
What is diffused reflection?
Diffused reflection is the irregular reflection of light from a rough surface, where parallel incident rays are reflected in different directions.
Why is it difficult for drivers to drive on wet roads at night?
Water fills and smooths out the irregularities of the road surface, causing specular reflection of oncoming headlights that creates a distracting glare.
What is Newton’s disc and how does it work?
Newton’s disc is a circular card painted with the seven colours of the rainbow that appears white when rotated rapidly due to the mixing of the colours.
Gallery
 
Want to print your doc?
This is not the way.
Try clicking the ··· in the right corner or using a keyboard shortcut (
CtrlP
) instead.