Class 9 - Science - Ch10 - Gravitation

Gravitation

Johannes Kepler -
proposed laws of planetary motion

NCERT Q & A, Study Notes, Numerical Problems, Questions asked in CBSE Papers.

Q1: What was geocentric model? Who proposed this theory?

Answer: Ptolemy a Greek mathematician and astronomer proposed geocentric model around 125 AD. According to this model, the earth is in the center and sun, other planets and stars move around it.
To explain retrograde motion of planets, he also proposed that those planet also move in small circle. The geocentric theory held valid till 1543 AD when Copernicus proposed heliocentric model.

CBSE Class 10 - History - Ch7: Print Culture and the Modern World

Print Culture and the Modern World

(MCQs)

Diamond Sutra - China (868AD)
credits:wikipedia

Q1: Printing was first developed in
(a) Japan
(b) Portugal
(c) China
(d) Germany


Q2(CBSE 2010): Which one among the following is an ancient name of Tokyo?
(a) Osaka
(b) Nagano
(c) Edo
(d) Gifu

CBSE Class 10 - Maths - CH8 - Introduction to Trigonometry

Introduction to Trigonometry

(MCQs asked in CBSE Papers)

Hipparchus: Father of Trignometry
Image credits:wikipedia

Q1: If cot A=12/5, then the value of  (sin A + cos A) × cosec A is :
(a) 13/5
(b) 17/5
(c) 14/5
(d) 1

Q2: cos 1° × cos 2° × cos 3° × ... × cos 180° is equal to :
(a)1
(b) 0
(c) 1/2
(d) –1

CBSE - Class 9 - Maths - Lines and Angles (Ex. 6.3)

Lines and Angles  

(NCERT Ex. 6.3 + Q & A from CBSE papers)

Points to remember

1. The sum of the angles of a triangle is 180º.

Impossible Triangle
(credits:openclipart)

2. If a side of a triangle is produced, then the exterior angle so formed is equal to the sum of the two interior opposite angles.

3. An exterior angle of a triangle is greater than either of its interior opposite angles.

4. If one angle of a triangle is a right angle, then the other two angles are acute angles. (Thus no triangle can have two right angles.)

5. The two acute angles in every right triangle are complementary.

6. The sum of all interior angles of an n-sided polygon is (n -2) × 180°

7. The sum of all exterior angles of an n-sided polygon is 360°.(one exterior angle at each vertex)

CBSE Class 9 English (Comm). SA1- Grammar - Verb Forms

Class 9 English (Comm). SA1- Grammar - Verb Forms

(Q & A from CBSE Examination)

Q(CBSE 2011): Complete the following by choosing the correct answer from the options given below:

(a) In a new audio recording, the leader of the Yemen branch of Al Qaeda, __________ by the Obama administration‘s alleged decision to authorize the assassination of an American - born Islamic cleric linked to the Ft. Hood shooting and attempted Christmas Day airplane terrorism  plots.
(I) warned Americans they will be harmed
(II) had warned Americans they will be harmed
(III) has warned Americans that they will be harmed.
(IV) has been warned Americans, they will be harmed

CBSE Class 9 - French SA1 Paper (Solved)

Class 9- French - SA1 Paper 2010
(SQP from CBSE)

CBSE Class 7 Science - CH10 - Respiration in Organisms (#eduvictors)(#class7Science)

Respiration in Organisms

NCERT Chapter Solutions and other Q & A

Q1: How breathing is different from respiration?

Answer:

S.No.	Breathing	Respiration
1	It involves the intake of oxygen and release of Carbon dioxide.	Respiration is more complex and it includes breathing as well as oxidation of food in cells to release energy.
2	It is a physical process i.e. exchange of gases.	It is a biochemical process in which food is broken along with the release of energy.
3	It involves breathing organs e.g. lungs in mammals.	It occurs at a cellular level