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Write any four ways by which AIDS virus spreads from an infected person to a healthy person.

Posted by Muskan Sultana 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Nakul Sharma 7 years, 3 months ago

1. Sexual contact

Yogita Ingle 7 years, 3 months ago

Sexual contact that involves semen, pre-cum, vaginal fluids or blood.
Direct blood contact, particularly through sharing injection drug needles or 'works' (cotton, cookers, etc).
Infections due to blood transfusions, accidents in health care settings or certain blood products. This is possible, although extremely rare.
Mother to baby (before or during birth, or while breastfeeding through breast milk)

ANSWER

Name the causative organism of cholera.

Posted by Muskan Sultana 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 3 months ago

Cholera is a bacterial disease caused by the bacterium ‘Vibrio Cholerae’. This type of bacteria is usually present in the contaminated foods. It is also found in the places where there is a lack of sanitation facilities. This disease was first discovered in the US during the 1800’s. Cholera disease has been causing severe issues to people from over hundreds of years.

ANSWER

What is the relative mass and absolute mass of an electron?

Posted by Shivam Yadav 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 3 months ago

Relative mass in the average atomic mass of all the isotopes present in percentage while absolute mass is the sum of number of protons and neutrons mass. For example the absolute mass of carbon is 12.0 amu while 12.01 is the average atomic mass of carbon on the basis of percentage of C-12, C-13 and C-14 isotopes.
Absolute mass of an electron – 9.108 X 10-³¹ kg
Relative mass of an electron – 5.45 X 10^-4 amu

Shivam Yadav 7 years, 3 months ago

Relative mass= 1/1840u and absolute mass = 9×10^-28

ANSWER

What is law of conservation of linear momentum ?

Posted by Vandana Arora 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Ved Jaw 7 years, 3 months ago

It means that momentum can neither be created nor destroyed.

ANSWER

Give summary of ch 7 diversity in living organisms

Posted by Vanshika Patel 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Ved Jaw 7 years, 3 months ago

It says how the organisms are classified on the basis of their characterstics. You just have to learn the criterion which decides which group an organism belongs to.

ANSWER

What is cathod ray?

Posted by Gayatri Gayin 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Gaurav Seth 7 years, 3 months ago

Cathode rays

Cathode rays consist of negatively charged material particles called electrons.
These rays deflect towards the positive plate of an electric field.
The charge to mass ratio (e / m) for the particles in the nature of the gas taken in the discharge tube.

ANSWER

At how many celsius water become ice

Posted by Vandana Arora 7 years, 3 months ago

CBSE > Class 09 > Science

3 answers

Bhargav Parate 7 years, 3 months ago

Zero degree celcius

Kirti Singh 5 years, 11 months ago

100degree celsius

Yogita Ingle 7 years, 3 months ago

The freezing point of water is the temperature at which it changes from a liquid into a solid. Pure or distilled water freezes at 32 degrees Fahrenheit (zero degrees Celsius). So, at zero degrees Celsius water become ice.

ANSWER

On suffering from fever which will lower down your body temperature more , ice or ice cold water?

Posted by Shivam Yadav 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Shivam Yadav 7 years, 3 months ago

The ice will lower down your body temeprature more rapidly than ice cold water because the melting point of ice is 0 degree celsius whereas the melting point of water is 100 degree celsius and also the ice water will evaporate quickly than the ice

ANSWER

That conekt the bone

Posted by Yash Kadam 7 years, 3 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

How does the sound produced by a vibrating object in a medium reach your ear

Posted by Naman Jain 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 3 months ago

When an object vibrates, the particles in the surrounding medium vibrate. These particles send the vibrations to adjacent particles and energy continues to transmit until it reaches our ears.A wave is a disturbance moving through a medium when the particles of a medium set the adjacent particles into vibration.The particles do not move forward, but the disturbance does.When these vibrations reaches our ears, the ears allow us to convert pressure variations in the air with audible frequencies into electric signals that travel through the brain via the auditory nerves.

Shivam Yadav 7 years, 3 months ago

Consider a bell. When the bell rangs what happens!!!!, the bell vibrates in small amount and that vibration collides with the surrounding layer of particles and this particles too vibrate in the form of back and for motion as we know that the sound wave are longitudnal wave. That vibrating particles collides with another layer of particle and this happens continously and reaches at a layer of the ear of a person is standing. As, by this vibration our eardum vibrates and it goes to the brain and this how we hear the sound

ANSWER

Two objects placed in a room , are not pulling each other . Why?

Posted by Sidharth Khurana 7 years, 3 months ago

CBSE > Class 09 > Science

3 answers

Yogesh Bansal 7 years, 3 months ago

They may be kept very far from each other

Sidharth Khurana 7 years, 3 months ago

Because other object also pull these objects

Sidharth Khurana 7 years, 3 months ago

467-

ANSWER

Define 1watt

Posted by Shivam Yadav 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Yug - 7 years, 3 months ago

No. Of (work done/no. of time taken)

Shivam Yadav 7 years, 3 months ago

1joule/1second

ANSWER

What do you understand by term 1 mole

Posted by Shruti Shruti 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Bhargav Parate 7 years, 3 months ago

Mole means no. of atoms of every element.

Shikhar Srivastava 7 years, 3 months ago

6.023×10^23

ANSWER

Why sound waves are called mechinical waves

Posted by Deepanshu Shrikanth 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 3 months ago

You should know that the mechanichal waves are those waves which require a medium for propogation. Sound needs a medium (solid, liquid or gas) for their propogation and can't travel without a medium. Therefore sound wave is a mechanical wave.
Mechanical waves is characterised by the motion of the particles of the medium. Sound needs a material medium like air, water, steel, etc. for its propagation. Hence, sound waves are called mechanical waves.

ANSWER

According to force of attraction I should be attracted with the friends sitting near me but why doesn't it happen

Posted by Sneha Pandey 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Abhinav Anurag 7 years, 3 months ago

Because the force acting between you and your friend is too small i.e. G= 6.67*10-11 and also there is newton's first law that you want to resist the change of position...

ANSWER

What is CFCs

Posted by Vivek Adhikari 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 3 months ago

CFCs (ChloroFluoroCarbons) are the chemicals used in airconditioners and refrigerators which cause destruction of ozone layer present in the stratosphere of the atmosphere.
CFCs form active chlorine in the presence of UV radiations. Radicals produced are Cl and ClO. These radicals destroy ozone by converting it into oxygen. Oxygen just is a gas which remains in the atmosphere.

Harsh Kumar 7 years, 3 months ago

It is chloro fluro carbon which used in refrigerator

ANSWER

kingdom monera

Posted by Ali Asger 5 years, 11 months ago

CBSE > Class 09 > Science

1 answers

Sreya Sailesh 7 years, 3 months ago

•unicellular •prokaryotic •Mode of nutrition: autotrophic or heterotrophic•eg:Blue green algae

ANSWER

What is pressure?explain

Posted by Rishabh Solanki 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Abhinav Anurag 7 years, 3 months ago

Force per unit area that is 1 meter, 1 centimeter, force = 1 newton only..

ANSWER

What is boyancy force

Posted by Rishabh Solanki 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Priya Verma 7 years, 3 months ago

The upward force exerted by the water on the object is known as upthrust or buoyancy force.

ANSWER

Difference between isotopes and isobar

Posted by Rishabh Solanki 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Bhargav Parate 7 years, 3 months ago

Isotopes - they have same atomic no. but different mass no. Eg- hydrogen, protinm,tritium. Isobars - they have different atomic no. but same mass no. Eg- argon, potasium, calcium

Aanchal Jaiswal 7 years, 3 months ago

ISOTOPES :- those element which have same atomic number but different atomic masses is called isotopes EX:- 17cl35, 17cl37 ISOBARS:- Those element which have same mass number but different atomic number is called isobars.. EX:- 20ca40, 18ar40

ANSWER

Why AIDS is a fatal disease?

Posted by Mangal Sain 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Mutyala Gayathri 7 years, 3 months ago

Aids do not directly kill the person but instead it effects the immune system in which small cold can become severe pneumonia. Tis loss of immune system stops curing a disease which leads to death of a person.

ANSWER

Which gas need for growth of plants

Posted by Mahadevan S 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Sreya Sailesh 7 years, 3 months ago

Nitrogen

ANSWER

What are reptiles

Posted by Ansh Rawat 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Horror Das 7 years, 3 months ago

repliles are a group of animals of vertebrata class . they have 3 chambered heart (exception crocodile who have 4 chambered heart). the have dry skin and dry scales. they do not need to lay their eggs in water lke those of amphibians.

Piyush Chaudhary 7 years, 3 months ago

Creeping vertebrates having dry skin with scales on them

ANSWER

What is a full form of rbc

Posted by Vikash Yadav 7 years, 3 months ago

CBSE > Class 09 > Science

3 answers

Yogesh Bansal 7 years, 3 months ago

Other name is erythrocytes

Bhargav Parate 7 years, 3 months ago

Red blood cells

Vikash Yadav 5 years, 11 months ago

Red blood cells

ANSWER

What is the atomic mass of iron

Posted by Yash Chaturvedi 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Bhargav Parate 7 years, 3 months ago

56

Harsh Arora 7 years, 3 months ago

56

ANSWER

What is the law of conservation of mass?

Posted by Sanjana Anand 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Gurleen Kaur 7 years, 3 months ago

Law of conservation of mass states that mass can neither be created nor be destroyed in a chemical reaction

ANSWER

Define kinetic energy ?

Posted by Kuldeep Raghuwanshi 7 years, 3 months ago

CBSE > Class 09 > Science

4 answers

Tanisha Saini 7 years, 3 months ago

It is a energy possessed by a particle due to it motion

Bhargav Parate 7 years, 3 months ago

Energy possessed by an object or body during motion is called kinetic energy.

Gurleen Kaur 7 years, 3 months ago

K.E. is the energy posses by a body due to its motion

Lakshya Sharma Lucky 7 years, 3 months ago

The object is in motion is defined as kinetic energy. Like 1/2mvsquare because velocity is directly propotional to kinetic energy . If we doubled the velocity the kinetic energy also be doubled.

ANSWER

What is bunkministerfullre

Posted by Aditya Benson 7 years, 3 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Different between mass and Wight

Posted by Ashu Patidar 7 years, 3 months ago

CBSE > Class 09 > Science

4 answers

Harsh Singh 7 years, 3 months ago

Mass is a scalar and weight is vector quantity.

Harsh Singh 7 years, 3 months ago

Weight is the force which attract a body towards its centre.

Harsh Singh 7 years, 3 months ago

Mass is the quantity of matter contain in the body

Aditya Benson 7 years, 3 months ago

The major difference is that mass is constant and weight is not constant Hope you satify with my answer

ANSWER

What are connective cells?

Posted by Ishwari Ramde 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Lakshya Sharma Lucky 7 years, 3 months ago

Cells wich connect our bones are called connective tissue

ANSWER

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