CBSE > Class 09 > Science | CBSE Board | Homework Help | myCBSEguide

No products in the cart.

Ask questions which are clear, concise and easy to understand.

Ask Question

What is the full meaning of STD

Posted by Sachin Kumar 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Tanisi Agarwal 7 years, 1 month ago

S.T.D : Subscriber trunk dialling (STD) (also known as subscriber toll dialling) is an term for allowing subscribers to dial trunk calls without operator assistance. This term however, is still widely prevalent in India to describe any national call made other than one's local

Gaurav Seth 7 years, 1 month ago

The full form of STDs is sexually transmitted diseases.

ANSWER

What is the second law of newton

Posted by Sachin Kumar 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Tanisi Agarwal 7 years, 1 month ago

The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

Angel Jindal 7 years, 1 month ago

Rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of the force

ANSWER

What is the defference between atom and ioan in hindi

Posted by Mayank Kumar 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Virus are spread though

Posted by Anusha Kushwaha 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 1 month ago

Viruses can be passed from one person to another by shaking hands, touching food, through water, or through the air when a person coughs or sneezes. Viruses can also be passed on by insect bites, animals, or through bad food. There are many viruses that can infect people and make them sick.

ANSWER

Applications of sonar

Posted by Parteek Inder Singg 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 1 month ago

The SONAR method is also called echo ranging. This technique is used to determine the depth of the sea and to locate underwater hills, valleys, submarine, icebergs, sunken ship etc.

Arnav Sharma 7 years, 1 month ago

Used in ships and submarine to check obstacle under water

ANSWER

Write the characteristics of sound and explain it?

Posted by Archna Toppo 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 11 months ago

Following are the main characteristics of sound wave:

Wavelength : Wave length is the length between two consecutive peaks, i.e. crest or two consecutive valleys, i.e. trough of a wave. Wave length is represented by Greek letter λ (lambda). Louder sound has shorter wavelength and softer sound has longer wavelength. The SI unit of wavelength is metre (m).
Amplitude : Magnitude of maximum disturbance on either side of the normal position or mean value in a medium is called amplitude. In other words, amplitude is the distance from normal to the crest or trough.
Time period: Time required to produce one complete wave is called time period or time taken to complete on oscillation is called the time period of the sound wave. In other words, time in which a wave moves a distance equal to its wavelength is called time period.
Frequency: The number of sound waves produced in unit time is called the frequency of sound waves. For example, if a source of sound produces 20 sound waves in one second then the frequency is 20 Hz.
Speed

ANSWER

What are the example of thomson modle

Posted by Riddhi Banderwal 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Saloni Tak 7 years, 1 month ago

Plum pudding

Darsh Kaur 7 years, 1 month ago

Water melon Christmas pudding

ANSWER

Important questions for annual examination

Posted by Nishant Nishant 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Nikhil Kumar 7 years, 1 month ago

All questions

ANSWER

What is eutrofication?

Posted by Ayush Sharma 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Samarveer Singh 7 years, 1 month ago

Excessive richness of nutrients in water bodies due to run off from land,causes a dense growth of plant at surface of the water body is called eutrophication.

Yogita Ingle 7 years, 1 month ago

Eutrophication refers to the nutrient enrichment in the water bodies leading to lack of oxygen and deadening of life supporting environment. Usually rapid increases in the nutrient status of a body of water happen, by both natural and occurring as a byproduct of human activity. It may be caused by run – off of artificial fertilizers from agricultural land, or by input of sewage or animal waste. This increased nutrient content of the water body causes excess growth of algae. This algal bloom covers the water surface, secrete toxins and reduce oxygen content of water. Oxygen deficiency may cause the death of aquatic animals.

ANSWER

What is unconsciousness

Posted by Prashant Shukla 7 years, 1 month ago

CBSE > Class 09 > Science

4 answers

Ayush Sharma 7 years, 1 month ago

While it is difficult to measure what exists in the unconscious, we know that even fleeting perceptions can leave lasting imprints on the unconscious mind long before one becomes aware of them.

Darsh Kaur 7 years, 1 month ago

It is a state when we don't know what is going on here and there. In this state we are unable to maintain our self

Yogita Ingle 7 years, 1 month ago

Unconsciousness is a state which occurs when the ability to maintain an awareness of self and environment is lost. It involves a complete or near-complete lack of responsiveness to people and other environmental stimuli.

Geetanand Yadav 7 years, 1 month ago

Behosh hona or not feeling good

ANSWER

Explain ratherford model with observation and conclusion

Posted by Sweety Muskan 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 1 month ago

Observations of Rutherford's scattering experiment:

Most of the fast moving α-particles passed straight through the gold foil.
Some of the α-particles were deflected by the foil by small angles.
Surprisingly one out of every 12,000 alpha particles appeared to rebound.

Conclusion of Rutherford's scattering experiment:

Most of the space inside the atom is empty because most of the α-particles passed through the gold foil without getting deflected.
Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.
A very small fraction of α-particles were deflected by very large angles, indicating that all the positive charge and mass of the gold atom were concentrated in a very small volume within the atom.

ANSWER

Why do we fall inside the water fastely then a volume containing body?

Posted by Arnav Sharma 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Geetanand Yadav 7 years, 1 month ago

We have small area covered due to which the byouncy force exerted by water on us is less and more on volume containing body.

ANSWER

Prove that energy remains constant in case of a freely falling body

Posted by Aarohi Singh 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

A boomerang is thrown at an angle to the ground, it moves in a curved path and falls back to the ground.The initial and final points of its path lie on the sams horizontal line.What is the work done by the force of gravity on the object?

Posted by Akshata Kumar 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

wooden cuboid has a mass of 10 kg the Length breadth and height of this wodden cuboid are 100cm 50 cm and 20 CM respectively find the pressure on the floor on which this block is kept

Posted by Madhavi Gottumukkala 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Why lysosome is called suicide bag ?

Posted by Suyash Majhi 7 years, 1 month ago

CBSE > Class 09 > Science

3 answers

Siddesh Lohkare 7 years, 1 month ago

Lysosomes is a organelle in the cell which contain digestive enzymes. If the cell gets damaged the lysosomes release the digestive enzymes these enzymes then clean the cell so lysosome s are called sucidal bags of the cell.

Anshika Gupta 7 years, 1 month ago

lysosomes are organelles which cleans our cell, when the cell got damages lysosomes goes against our cell and releases toxic enzymes, which make our cell die leading to suicide of cell

Kamlesh Singh 7 years, 1 month ago

Cause it kill the non usaable thigs which harmfull for us and after killing them it dies

ANSWER

What exactly is time dilation??

Posted by Deeraj R 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Prove law of conservation of momentum?

Posted by Parijat Sinha 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Gaurav Seth 7 years, 1 month ago

Law of conservation of momentum states that total momentum of system remains conserved in the absence of external force.

Proof:

Consider a body of mass m₁ moving with veocity  striking against another body of mass m₂moving with velocity .

Let, the two bodies remain in contact with each other for a small interval  .

Let,  be the average force exerted by mass m₁ on m₂ and let  be the force on m₂ due to m_1.
Let, v₁ and v₂ be the velcoities of two bodies after collision.

Momentum of mass m₁ before collision = m₁u₁

Momentum of mass m₂ after collision = m₂
Momentum of mass m₁ after collision = m₁v₁

By using the defintion of impulse, change in momentum of mass m₁ is,

ANSWER

Name the fourth and fifth states of matter?

Posted by Parijat Sinha 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Arpit Raghuwanshi 7 years, 1 month ago

4) plasma, 5) (B.e.c) bose einstein condensate are the fourth and fifth state of matter

Gaurav Seth 7 years, 1 month ago

The fourth state of matter is Plasma. Plasma is the most abundant state of matter in the universe. A majority of the stuff in space is Plasma. It is also plays an important part in safe, unlimited and renewable energy. Plasmas are very hot, and they vaporize anything they touch.
The fifth state of matter is BEC (Bose-Einstein Condensate). A Bose–Einstein condensate is a state of matter formed by bosons cooled to temperatures very near to absolute zero (0 kelvin or -273.15°C). Under such supercooled conditions, a large fraction of the atoms collapse into the lowest quantum state, at which point quantum effects become apparent on a macroscopic scale.

ANSWER

Session ending final exam blue print.

Posted by Sanjay M 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Calculate the Al ions in 0.051g of Al²O³

Posted by Jyoti Aggarwal 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Gaurav Seth 7 years, 1 month ago

Molecular weight of Al₂O₃ = 102 g

102 g of Al₂O₃ contains 6.022X10²³ molecules

0.051g of Al₂O₃ contain X number of molecules

X = 0.051 X 6.022X10²³/102 = 0.003 X 10²⁰

X = 3 X 10²⁰

1 molecule of Al₂O₃contains – 2 Al⁺³ions

3 X 10²⁰molecules contains – 2 X 3 X 10²⁰

= 6 X 10²⁰Al⁺³ ions
∴0.051 g of Al₂O₃ contains 6 X 10²⁰Al⁺³ ions

ANSWER

What is smog ? give its example

Posted by Anshika Singh 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Paras Sharma 7 years, 1 month ago

It is a mixture of smoke and fog. Smoke + Fog = Smog. Example you can see the atmosphere after the diwali, it is smog due to fire crackers cracking on a large amount.

ANSWER

What factors decide the movement of gentle breeze, strong wind and terrible strom?

Posted by Nandita Mishra 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Derive equation law of conservation of momentum

Posted by Rishi Singh 5 years, 11 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

How is culture fishing different from capture fishing?

Posted by Nikhil Verma 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Mandeep Kharb 7 years, 1 month ago

If you have schand book of biology and have not issue from the library you get your answer completely

ANSWER

Calculate the number of atoms in 52g of helium

Posted by Sahil Ransing 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Write down the formula of sodium sulphate using criss cross method

Posted by Vikram Bhadoriya 7 years, 1 month ago

CBSE > Class 09 > Science

3 answers

Rajkumar Sharma 7 years, 1 month ago

Good question

Priyanshu Patel 7 years, 1 month ago

Sodium sulphate Na so4 1 2 Using criss cross method Na2So4

I'M Aadarsh 7 years, 1 month ago

Na ?+1. SO4 ?-2 :- Na2SO4

ANSWER

Name the devices based on archemide's principal

Posted by Amit Sharma 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Priyanshu Patel 7 years, 1 month ago

Hydorometer

Vinod Singh 7 years, 1 month ago

Lactometer

ANSWER

We have atomic no. Is 17 and atomic mass is 35 so what is the no. Of neutron

Posted by Keshav Sain 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Pranathi Potluri 7 years, 1 month ago

No. Of nuetrons = the mass no.- protons ( atomic no.) Therefore it is 35-17=18 so no. Of neutrons are 18

ANSWER

What are cytosole?

Posted by I'M Aadarsh 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Pranathi Potluri 7 years, 1 month ago

Cytosol is the fluid part of the cytoplasm. It is viscous and nearly homogeneous and a crystallocolloidal liquid that contains a number of substances like water ,ions , enzymes ect....

ANSWER

Page 537 of 1369

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Google Play

Download myCBSEguide App