Big relief for the CBSE students of class 9th to 12th. School syllabus has been slashed by 30% for students on account of the extraordinary situation in India and the world because of Corona virus pandemic. The courses has been rationalised to lighten the load while retaining the core concepts. In a tweet, Human Resource […]
Arithmetic Progressions Previous Years Questions For what value of k will k + 9, 2k – 1 and 2k + 7 are the consecutive terms of an A.P. ? [CBSE 2016] [1 Mark] In an AP, if the common difference is -4 and the seventh term is 4, then find the first term. [CBSE 2018] […]
Quadratic Equations – Previous Years Questions The quadratic equation x2 – 4x + k = 0 has distinct real roots if k = 4 k > 4 k = 16 k < 4 [CBSE 2020] [1 Mark] Write the discriminant of the quadratic equation (x + 5)2 = 2(5x – 3). [CBSE 2019] [1 Mark] […]
Pair of Linear Equations in Two Variables – Previous Years Questions The pair of linear equations y = 0 and y = -6 has a unique solution no solution infinitely many solution only solution (0,0) [CBSE 2020] [1 Mark] Solve the following pair of linear equations:3x – 5y = 42y + 7 = 9x [CBSE […]
The Fundamental Unit of Life Important Questions Define nucleoid. . Why mitochondria is called the powerhouse of the cell ? Why is the inner membrane of mitochondria deeply folded ? Where is protein synthesized in a cell ? Explain. Name the three solutions that can be used to stain the cell while observing it under […]
Control and Coordination Notes Stimulus:- The change in the environment to which an organism respond and react is called stimulus. Receptors:- The group of cells present in sense organs which are sensitive to change in environment are called receptors. There are five types of receptors:- Gustatory receptor Olfactory receptor Photo receptor Phono receptor Thermo receptor […]
Periodic Classification of Elements Important Questions “Atomic number of an element is considered to be a more appropriate parameter than its atomic mass for a chemist.” Take the example of element X (atomic number 13) to justify this statement. How many triads did Dobereiner identify from the existing elements during his time ? Give an […]
Periodic Classification of Elements Notes Döbereiner’s triads:- Dobereiner arranged elements with similar properties into groups having three elements each and called those groups triads.When the three elements in a triad were written in the order of increasing atomic masses, the atomic mass of middle element was roughly equal to the average atomic masses of other […]
Class 9 Polynomials Important Questions Using suitable identity determine the value of :- (17)3 + (-12)3 + (-5)3 64m3 – 343n3 Factorise :- 2y3 – 4y2 – 2y + 4 2×2 + 7x + 3 Factorise : (a-b)3 + (b-c)3 + (c-a)3 If (a + b + c) = 15 and a2 + b2 + […]
Atoms and Molecules Notes Laws of chemical combination:- Law of conservation of mass:- It states that mass can neither be created nor be destroyed in a chemical reaction. Or,It states that the total mass of reactants is equal to total mass of products in a chemical reaction. Law of constant proportion:- It states that in […]