CBSE ADDA

The Central Board of Secondary Education (CBSE) intends to keep the Central Teacher’s Eligibility Test (CTET) in online mode across 22 Cities in India. The traditional paper pencil mode of exam will also be in practice; last year nearly 790,000 students have registered for CTET. CTET 2011 was conducted by CBSE on 26 June 2011 (Sunday) at 1178 Centers in 86 Cities across the Country and  2 Centers are in abroad. CTET 2012 is likely to be held during January to June 2012; the test could go online across all major cities in India including Bangalore. CTET will have two papers, Paper I will be for teacher posts to classes I to V, while Paper II will be for teacher posts for classes VI to VIII. You can learn more about CTET. Last year only 14% managed to qualify in the written test; as many as 617,131 candidates couldn’t clear the test.

Class 9 Chapter Work and energy Solved Numerical problems 1. A force of 10N causes a displacement or 2m in a body in its own direction. Calculate the work done by force. 20j Solution: the work done by force = F x S = 10 N x 2m = 20 J 2. How much force is applied on the body when 150 joule of work is done in displacing the body through a distance of 10m in the direction of force?(15 N) Solution: W = F x S Þ F = w/s = 150/10 = 15 N 3. A body of 5kg raised to 2m find the work done(98j) Solution: T he work done to raise a body = PE = mgh = 5kg x 9.8 x 2 = 98 joule 4. A work of 4900j is done on road of mass 50 kg to lift it to a certain height. Calculate the height through which the load is lifted. (10m) Solution: work done on road to lift = mgh Þ 4900 = 50 x 9.8 h Þ h = 10m 5. An engine work 54,000J work by exerting a force of 6000N on it. What is the displacement of the force . (9m) Solution: S = W/F = 54,000J/6000N = 9m 6. A force of 10N acting on a body at an angle of 60 deg. with the

CBSE PHYSICS:Class IX Work Power and Energy notes(Physics) : Work :   In our daily life anything that makes us tired is known as  work . For example, reading, writing, painting, walking, etc. In physics work (W) is said to be done, when a force (F) acts on the body and point  of application of the force is displaced (s) in the direction of force. Work done = force x displacement     W          =     F       x       s (i) If the body is displaced in the same direction of force, Work done is positive Read more »

CBSE PHYSICS Class 10 Physics The Humane Eyes Notes :   IMPORTANT CONCEPTS: Human eye can be treated as an optical instrument. Light rays coming from the object to be seen enter the eye through Cornea and fall on the eye lens through the pupil of the eye. Eye lens being double convex lens forms a real inverted and smaller image of the object on the retina. The retina contains numerous light sensitive cells which are activated by the light falling on the retina and generate electrical signals which are sent to brain via optic nerve and the brain processes this information and we perceive objects as they are. The human eye has the following parts:- (a) Cornea: -The transparent spherical membrane covering the front of the eye. (b) Iris: -The coloured diaphragm between the cornea and lens. (c) Pupil: -The small hole in the iris. (d) Eye lens: -Its is a transparent lens made of jelly like material. (e) Ciliary muscles: -These muscles hold the lens in position. (f) Retin