1. Elasticity:
It is the property of a material by which it tries to regain its original configuration after the removal of the deforming force applied to it. Example of perfectly elastic solid, quartz, phosphor, bronze.
2. Plasticity:
It is the property of a body by virtue of which it does not regain its original shape and size even after the removal deforming force, is called plasticity.
CBSE Class 11 - Mathematics - Limits and Derivatives Part-9
You have learnt about finding derivatives using the first principle in part-7 and part-8. Let us proceed further. Here is a summary of theorems on differentiation.
Topics Covered: Work, Power and Energy
Q1: A bullet is fired from a rifle, If the rifle recoils freely, then the kinetic energy of the rifle will be:
(a) same as that of bullet
(b) more than that of bullet
(c) less than that of bullet
(d) none of these
Q2: A body of mass 2 kg, initially at rest, is acted upon simultaneously by two forces, one of 4N and the other of 3N, acting at right angles to each other. The work done by the body after the 20s is
(a) 500 J
(b) 1250 J
(c) 2500 J
(d) 5000 J
Salts/Compounds Colour
1. Potassium dichromate, K₂Cr₂O₇ Orange
2. Potassium permanganate, KMnO₄ Violet
3. Ferric tetra-oxide, Fe₃O₄ Black
4. Ferrous sulphate, FeSO₄.7H₂O Green
5. Ferric sulphate, Fe₂(SO₄)₃ Yellow
6. Ferric hydroxide, Fe(OH)₂ Green
(General Science)
Structure of Atom
1. Discovery of Electron — Discharge Tube Experiment:
In 1879, William Crooks studied the conduction of electricity through gases at low pressure. He performed the experiment in a discharge tube which is a cylindrical hard glass tube about 60 cm. in length.
Mass of electron = 9.109534 x 10⁻³¹ kg
Charge on a electron = (-) 1.602 x 10⁻¹⁹ C
2. Properties of Cathode Rays
(i) Cathode rays travel in straight line.
(ii) Cathode rays start from cathode and move towards the anode.
For Class 11/Class 12 Physics - NEET - JEE
Physics deals with the study of the basic laws of nature and their manifestation in different phenomena. The basic laws of physics are universal and are applied in widely different contexts and conditions. Physics is a basic discipline in the category of natural sciences which also includes other disciplines like Chemistry and Biology. The word physics comes from a Greek word meaning nature.
Here is a partial list of Physicists and their contributions in various fields of physics.
Topics Covered: Laws of Motion, Circular Motion
| No. | Discovery | Scientist | Year |
|---|---|---|---|
| 1. | Proton | Rutherford | 1919 |
| 2. | Neutron | James Chadwick | 1932 |
| 3. | Atom | John Dalton | 1808 |
| 4. | Atomic Structure | Neil Bohr & Rutherford | 1913 |
| 5. | Radioactivity | Henry Becquerel | 1896 |
| 6. | Radium | Madam Curie | 1898 |
| 7. | Raman Effect | CV. Raman | 1928 |
| 8. | X-Rays | Roentgen | 1895 |
| 9. | Photoelectric effect | Albert Einstein | 1905 |
| 10. | Periodic table | Mendeleev | 1888 |
| 11. | Nuclear Reactor | Anrico Fermi | 1942 |
| 12. | Wireless Telegram | Marconi | 1901 |
| 13. | Dynamite | Alfred Nobel | 1867 |
