Light is invisible until it hits an object. It can only be visible to us whenever it get scattered or bounced off the dust particles in the intervening medium. We can see the source of light like stars at night as they are too dim to light up much but that light does hit our eyes and therefore we see the light. The above discussion on visibility of light is only confined to the electromagnetic radiation of wavelength from 400 nm to 700 nm which is called visible light, as these electromagnetic radiations gives the sensation of sight.

Numerical Problems Based on Class 11 Physics Units and Measurement
Numerical Problems Based on Class 11 Physics Units and Measurement Q.1. Convert a power of one mega watt on a system whose fundamental units are 10 kg, 1 dm and 1 minute. Solution: 2.16 x 1012 in new units Q.2. The moon is observed from two diametrically opposite points A and B on earth. The… Read more

Class 10 Social Science PPT for Online Teaching
We are providing Highly Animated Class 10th Social Science PPTs. Make your online teaching interesting with our interactive highly animated PowerPoint presentations for Social Science. A must buy for teachers teaching online. Get PowerPoint presentations for complete class 10 Social Science SST. These PPTs are very useful for teaching purpose. These Social Science PPTs based on… Read more

Class 10 Maths PPT for Online Teaching
Class 10 Maths PPT for Online Teaching We are providing class 10th Maths PPTs. Make your online teaching interesting with our interactive highly animated PowerPoint presentations for Maths. A must buy for teachers teaching online. Get PowerPoint presentations for complete class 10 Maths. These PPTs are very useful for teaching purpose. These Maths PPTs based… Read more

Revision Notes for Class 12 Physics Chapter 10 Wave Optics
Wavefront : The locus of all particles of the medium vibrating in the same phase at a given instant is known as wavefront.Depending on the shape of sources of light, wavefront can be of three types>> Spherical wavefront : When the source of light is a point source, the wavefront is spherical.>> Cylindrical wavefront :… Read more

Algebraic Identities
What is an Algebraic Identity?An algebraic identity is an algebraic equation that is true for all values of the variables occurring in it. Important Algebraic Identities: (i) (x + y)2 = x2 + 2xy + y2 (ii) (x – y)2 = x2 – 2xy + y2 (iii) x2 – y2 = (x + y)(x – y) (iv) (x + a)(x +… Read more

Extra Questions for Class 10 Maths Chapter 3 Linear Equations Based on Graphical Method of Solving Linear Equations
Graphical Method of Finding Solution of a Pair of Linear Equations To solve the pair of linear equation proceed as below. Step 1: Draw a graph for each linear equation. Step 2: Find the coordinate of the point of intersection of the two drawn lines. Step 3: The coordinates of the point of intersection of… Read more

Extra Questions for Class 10 Maths Chapter 4 Quadratic Equations Based on Nature of Roots
Extra Questions for Class 10 Maths Chapter 4 Quadratic Equations Nature of Roots of a Quadratic Equation Let the given equation be ax2 + bx + c = 0, where a = 0. Then, the discriminant is given by D = (b2 – 4ac) . And, the roots of the given equation are Case 1:… Read more

Word Problems on Quadratic Equations for Class 10
Word Problems on Quadratic Equations for Class 10 Here we are providing Word Problems on Quadratic Equations for Class 10 Maths. These questions are prepared by subject experts. Students can use these questions for better practice and to obtain marks in the exam. Q.1. The product of two consecutive positive integers is 306. Find the… Read more

Case Study Questions for Class 12 Maths Chapter 1 Relations and Functions
Case Study Questions for Class 12 Maths Chapter 1 Relations and Functions Question 1: Sherlin and Danju are playing Ludo at home during Covid19. While rolling the dice, Sherlin’s sister Raji observed and noted the possible outcomes of the throw every time belongs to set {1, 2, 3, 4, 5, 6}. Let A be the… Read more

Case Study Question for Class 12 Physics Chapter 7 Alternating Current
Case Study Question for Class 12 Physics Chapter 7 Alternating Current Question 1: Read the para given below and answer the questions that follow: Resonant Series LCR Circuit. When the frequency of ac supply is such that the inductive reactance and capacitive reactance become equal, the impedance of the series LCR circuit is equal to… Read more