CLass 9 - Maths - Ch12 - HERON’S FORMULA

HERON’S FORMULA

(Questions from CBSE Papers)

Points to Remember

1. Area of a triangle = ½ base × height
As in figure,
Area =  ½ BC × AM square units.



2. When the triangle is right angled.

Area of a triangle = ½ base × height

 = ½ × Product of sides containing the triangle.

CBSE Class 8 - Science - Coal and Petroleum

Coal and Petroleum

Oil Drilling

(NCERT Chapter Answers and Q & A)


Q1:What are the advantages of using CNG and LPG as fuels?
Answer: The advantages of using CNG and LPG as fuels are:

1. They are used as non-polluting fuels to transport vehicles.
2. CNG is used for power generation and is a cleaner fuel.
3. LPG can be used directly for burning in homes and factories.
4. LPG and CNG has virtually no ash particles left after burning.

Q2:Name the petroleum product used for surfacing of roads.
Answer: Bitumen is the petroleum product used for surfacing of roads.

CBSE Class 9 - Social Science - Physical Features of India

Physical Features of India

Concepts Maps & MCQs

1. Physiographic divisions

Class 6 - Science - CH9 - The Living Organisms and Their Surroundings

The Living Organisms and Their Surroundings

Cockatoo - Can it survive without mangrove?

(NCERT Chapter Solution and other Q & A)

Q1: What is a habitat?
Answer: The surroundings where plants and animals live, is called their habitat. A habitat provides suitable climatic conditions like food and shelter so that plants and animals can live there.

Q2: Do all organisms live in same habitat?
Answer: No all organisms do not live in same habitat. Some may share the habitat e.g. lion and deer. For example camel can live in deserts only while frogs can survive in fresh/rain water.

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