CBSE Class 8 - Science - Force, Pressure and Friction (Short Answer Type Questions)(#eduvictors)(#cbseClass8Science)

Force, Pressure and Friction 

(Short Answer Type Questions)

CBSE Class 8 - Science

Q1: Why do porters place on their heads a round piece of cloth?

Answer: To reduce pressure.
Round piece of cloth increases contact surface areas, thus reduce the pressure.


Q2: It is convenient to pull the luggage fitted with rollers, why? 

Answer: Because rollers reduce friction. Rolling friction is much less than sliding friction.


Q3: lf we apply a force on a body and the body is still in rest. Is there any frictional force acting on the body? If yes then how?

Answer: Yes. Static friction is acting on it in opposite direction to the applying force. Thus, resultant force is zero.


Q4:  Sliding friction is less than static friction, how? Explain by an example.

CBSE Class 8 - Science - Chapter 18 - Pollution of Air and Water (Worksheet)(#eduvictors)(#class8Science)

Pollution of Air and Water (Worksheet)

CBSE Class 8 - Science - Chapter 18

All organisms including plants, animals (including human beings) and micro-organisms live in a habitat and interact with the ecosystem. Both biotic and abiotic components constitute environment. A harmful change in environment due to pollution cause discomfort and affect the lives of living beings.

Fill in the blanks

1. Substances that cause harmful changes in the air, soil or water are called ___________.


2. Incomplete burning of fossil fuels, like petrol and diesel, results in the production of colourless, odourless and toxic gas called ______________.


3. ________ is a mix, in the air, of smoke and chemicals with fog.


4. CFCs contribute to the depletion of the ________ layer that protects us from the harmful ultraviolet rays of the sun.

CBSE Class 10 - Physics - Light - Image Formation By A Plane Mirror (Q & A Part-3)(#cbsenotes)(#eduvictors)

Light - Image Formation By A Plane Mirror

(Q & A Part-3)

CBSE Class 10 - Physics

CBSE Class 8 Science - Synthetic Fibres and Plastics (Worksheet) (#cbsenotes)(#eduvictors)

Synthetic Fibres and Plastics 

CBSE Class 8 Science 

(Worksheet) 

Fill in the blanks

1. A synthetic fibre consists of numerous ________ joined together to form a large polymer.

2. Cotton is an example of _______ fibre.

3. Plastics are ________ conductors of electricity.

4. __________ soften or melt on heating.

Amazing Human Body - Quick Facts (#humanbody)(#eduvictors)

Amazing Human Body - Quick Facts 

1.  The hardest bone in the human body is the jawbone.

2.  The number of eye blinks varies greatly from about 29 blinks each minute if you are talking to someone to only 4 blinks each minute if you are reading.

3.  The average human blinks 25 times per minute.

4.  A nail takes around 6 months to grow from base to the tip.

5.  Each second 10,000,000 cells die and are replaced in your body.

Class 8 - Science - Chapter - Coal and Petroleum - Very Short Questions and Answers (#cbsenotes)(#eduvictors)

 Class 8 - Science

Coal and Petroleum

Very Short Questions and Answers

Q1: Name two each of the exhaustible and inexhaustible natural resources.

Ans: Petroleum and Coal



Q2: Write the name of two natural resources other than coal and petroleum.

Ans: Air, Forests, and Water



Q3: Why are air, water, and soil called natural resources?

Ans: Air, water, and soil are provided by nature, so they are called natural resources.


Q4: Why are coal, petroleum and natural gas called fossil fuels?

Ans: Coal, petroleum and natural gas are formed by fossils, so they are called fossil fuels.


Q5: What are fossil fuels?

Ans: Fossil fuels are the energy-rich components of carbon which were made by the decomposition of plants and animals buried under the earth, long-long ago.

CBSE Class 8 - Science Annual Sample Question Paper (2018-19) (Set-1)(#eduvictors)(#cbsenotes)

CBSE Class 8 - Science
 Annual Sample Question Paper (2018-19)
(Set-1)

Getting good marks is very important for students of class 8. For this one must practice and attempt sample question papers within time limits.

Here follows a sample question paper on Science subject that will help you revise and practice.

Help Guide(s) on Class 9 Science:

1. Class 8 Science Book (Lakhmir Singh) 

CBSE Class 8 - Science - Chemical Effects of Current (Worksheet)(#cbsenotes)(#eduvictors)(#class8Science)

Chemical Effects of Current 

Class 8 - Science 

(Worksheet)

Q1: Fill in the blanks

a. If electrodes are immersed in water and current is passed, bubbles of ________ and _______ are produced.

b. A coating of ______ is deposited on the iron to protect it from corrosion and formation of rust.


Q2: Circuit of the tester may be complete yet the bulb may not glow. Why?

Answer:
_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________


Q3: Why does a bulb glow when an electric current is passed through it?

Answer:
________________________________________________________________________

________________________________________________________________________

CBSE Class 8 - Science - Chapter 13 - Chemical Effect of Electric Current (Worksheet)(#cbsenotes)(#eduvictors)

Class 8 - Science 

Chapter 13 - Chemical Effect of Electric Current 

(Worksheet)

Fill in the blanks

1. Static electricity was first observed by _________, a Greek scientist, more than 2500 years ago.


2.  is the process in which an electric current is passed through a liquid, causing a chemical reaction to take place.


3. Most liquids that conduct electricity are solutions of _______, _______ and ______________.


4. When electricity is passed through tap water, the gases ________ and ______are evolved.

CBSE Class 8 - Science - Chapter 9 - Reproduction in Animals (Worksheet)(#cbsenotes)(#eduvictors)

Reproduction in Animals 

(Worksheet)

Fill in the blanks with suitable word(s).


1. The testes are located within a muscle bag called _________.


2. Amoeba is most commonly reproduced by ____________.


3. Butterfly in its development from larva to an adult shows __________.


4. Development of baby (foetus) takes place inside _________.


5. Inside mammals the fertilisation takes place in ________ or __________.

CBSE Class 8/9 - Science - Rare Species of Animals Found in National Parks (#cbsenotes)(#eduvictors)

Rare Species of Animals
Found in National Parks

Wildlife of India is a great natural heritage. Efforts are being made to protect and  preserve biological diversity of our country under various programs. India has preserved vast tracts of natural habitats, birds and plants in its 551 Wildlife Sanctuaries, 96 National Parks, 25 Wetlands and 15 Biosphere Reserves spread almost in all the states of India.

The purpose of establishing national parks is “to conserve the natural and historic objects and the wild life and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.”

CBSE Class 6 - 10 - Scientific Discoveries and Inventions Quiz (#sciencequiz)(#eduvictors)

Scientific Discoveries and Inventions Quiz

Q1: Who discovered the first antibiotic?

(a) W Fleming
(b) C Waksman
(c) Louis Pasteur
(d) A Fleming


Q2: Who invented the Safety razor?

(a) Gillette
(b) Nikola Tesla
(c) Steve Job
(d) Lar Strauss


Q3: X–rays were discovered by

(a) Edison
(b) Roentgen
(c) Marie Curie
(d) Van Lue

CBSE Class 8 - Science - CH10 - Reaching Age of Adolescence (Worksheet)

Reaching Age of Adolescence 

(Worksheet)

1. Adolescents become capable of reproduction when their ___________ and ________ begin to produce gametes


2. In human females the reproductive phase of life begins at________ and lasts till the age of ________ years.


3. __________ no. of chromosomes are present in the human gametes.


4. __________ and _________ are sex chromosomes.


5. An ovum has __________ sex chromosome while a sperm has _________ sex chromosome.

Science Quiz for CBSE Class 8 Students (#cbsenotes)(#eduvictors)

Science Quiz for CBSE Class 8 Students

Science plays a crucial role in setting the progressive path of our society. It is one way of knowing about the world. Science is a seamless web of knowledge. It is the search for truth and knowledge. Scientists suggest explanations of why things are as they are, and then they test those explanations, using experiments.

Multiple Choice Questions (MCQs) are by and large perceived as the most broadly material and helpful ways assess your knowledge. They could be utilized to quantify the most vital instructive results - information, comprehension, judgment and critical thinking.

The scope of science stretches far and wide. The best time to educate students in scientific approach and critical thinking is by making sure that the curriculum is created keeping this vision in mind. NCERT Books are specially designed keeping such objectives in mind.

Based on Class 8 Science NCERT book, follwoing are the MCQs available to help students learn their lessons and assess their knowledge.

Class 8 - Science - Combustion and Flame - Study Points (#cbsenotes)(#eduvictors)

CBSE Class 08 Science 

Study Points

Chapter 6: Combustion and Flame

⑴ Combustion: The process of burning a substance in the presence of air (oxygen) and undergoes a chemical reaction to produce heat and light.

⑵ The substances which burn in the air are called combustible.

⑶ Oxygen (in air) is essential for combustion.

⑷ During the process of combustion, heat and light are given out.

⑸ Ignition temperature is the lowest temperature at which a combustible substance catches fire.

⑹ Types of combustion: The type of combustion differs depending on the type of fuel. Based on nature and intensity, combustions are classified into three types. They are:
        (i) Rapid combustion
        (ii) Spontaneous combustion
        (iii) Explosion

⑺ The calorific value of a fuel is expressed in kilojoules per kilogram (kJ/kg).

CBSE Class 10 - Biology - Reproduction in Plants - Very Short Questions Answers (#cbsenotes)(#eduvictors)

Reproduction in Plants 

Class 10 Biology

Stamen, Anthers: Credits: Sandeep Handa

Very Short Questions Answers

Q1: Write two ways in which pollination may occur in plants.

Answer: The two ways in which pollination may occur in plants are:
⑴ Self-pollination.
⑵ Cross-pollination.


Q2: Name the three agents of pollination.

Answer: The three agents of pollination are:
⑴ Insect
⑵ Wind
⑶ Water


Q3: Name any three agencies for dispersal of seeds.

Answer:
⑴ Wind
⑵ Water
⑶ Man and animals, birds, bats, squirrels.

CBSE Class 8 - Science - Synthetic Fibres and Plastics (MCQs) - NCERT Exemplar Answers (#cbsenotes)(#eduvictors)

Synthetic Fibres and Plastics

Multiple Choice Questions

Question 1: Pick the synthetic fibre out of the following.

(a) Cotton
(b) Nylon
(c) Jute
(d) Wool


Question 2: Which of the following is a source of rayon?

(a) Wool
(b) PET
(c) Wood pulp
(d) Silk


Question 3: Polycot is obtained by mixing

(a) nylon and wool
(b) polyester and wool
(c) nylon and cotton
(d) polyester and cotton

NCERT Class 8 - Science - Chapter: Force and Pressure (Worksheet) (#cbsenotes)(#eduvictors)

Force and Pressure 

Class 8 - Science

(Worksheet)

Fill in the blanks

1. Muscular force is an example of _______ force.

2. Oil is applied to machines to reduce _______ force.

3. S.I unit of pressure is ____________.

4. S.I. unit of force is _____________.

5. If the area of contact is increased, then pressure ______ _.

6. Pressure in solid depends upon ________________ and ____________.

Class 6/7/8/9/10 Entrance Tests/NTSE/CTET/NDA - General Science Quiz (2018) (#eduvictors)

General Science Quiz 

Q1: Which of the following is not example bio-mass energy source?

(a) Wood
(b) Gobar gas
(c) Atomic energy
(d) Coal


Q2: The scientific study of earthquakes is known as 

(a) Seismology
(b) Cosmology
(c) Ecology
(d) Pathology


Q3: Which of the following is a plant hormone?

(a) Insulin
(b) Thyroxin
(c) Estrogen
(d) Cytokinin

CBSE Class 8 - Science - Microorganisms - Friends Or Foes (Questions and Answers) (#cbsenotes)(#eduvictors)

Microorganisms – Friends or Foes (Q & A-2)

Q1: Fill in the blanks:

a. Microorganisms may be unicellular or ___________.

b. __________ bacteria help to make curd from milk.

c. Disease-causing microorganisms are called _______.

d. Ammonium salt in the soil is converted first into nitrites by _________ bacteria.

e. _______ coagulation takes place only when milk is hot.

f. Salting draws out _______ from food.

g. Nitrate in the soil is converted by _________ bacteria into nitrogen gas.

h. The process of preventing food spoilage by chemical or physical methods is called food ________.

Answer:

a. Multicellular

b. Lactobacillus

c. pathogens

d. Nitrifying

e. Casein

f. water

g. denitrifying

h. preservation