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Write a short note on Sonar

Posted by Krish Krish 6 years, 1 month ago

1 answers

.. ... 6 years, 1 month ago

Sonar (sound navigation and ranging) it is a device that uses ultrasonic waves to measure distance,direction and speed of underwater objects. The transmitter produces and transmit ultrasonic waves.These waves travel through water and after striking the objects on seabed,get reflected back and are sensed by the detector.The detector converts ultrasonic waves into electrical signals which are interpreted. The time taken for the echo to return to ship is measured by sonar apparatus.The distance of underwater object is then calculated from time taken by echo to return.The time it takes for an echo to return is used to find out how far away something is. 2d=v*t d=distance from ship to the bed of the sea v=speed of sound through seawater t=time interval between transmission and reception of ultrasound signal.

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What is an embryo

Posted by Sparshika Singh 6 years, 1 month ago

CBSE > Class 07 > Science

2 answers

Avengers Endgame Koppula 6 years, 1 month ago

The zygote develops into an embryo

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Ramakant Sharma 6 years, 1 month ago

Form of zygote is known as embryo

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How many chambers are in our body

Posted by Parul Sharma 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Nishant Sharma 6 years, 1 month ago

4 chambers

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State difference between acids and bases.

Posted by Soul Hritik 6 years, 1 month ago

CBSE > Class 07 > Science

5 answers

Naman Ahden 6 years, 1 month ago

Acids are corrosive in nature, they turn blue litmus red eg-: hydrochloric acid. Ph value is less than 7 Bases feels slippery to touch, they turn red litmus blue example-: magnesium hydroxide. Ph value is more than 7

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Pragya Gupta 6 years, 1 month ago

* Acids are the substrances which are sour in taste. * Base are the substrances which feel slippery. * Acid + base = salt and water

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Shameem Shammi 6 years, 1 month ago

Acids are sour in taste It turn litmus paper

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L.Nagaraj L.Nagaraj 6 years, 1 month ago

Acids are substance which are sour. Bases are substance which are slippery eg: soap

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Shivdeep Dharme 6 years, 1 month ago

Acid are salty and base are sofay

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Differenciate between arteries and viens

Posted by Simarpreet Kaur 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Aaradhya Baghla 6 years, 1 month ago

Arteries carry oxygenated blood and veins carry deoxygenated blood

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What is respetory

Posted by Tanisha Singh 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 1 month ago

The respiratory system also called respiratory apparatus is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. Through breathing, inhalation and exhalation, the respiratory system facilitates the exchange of gases between the air and the blood and between the blood and the body’s cells. The respiratory system also helps us to smell and create sound.

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Is capillary a type of blood vessel ??

Posted by Ananya Nahar 6 years, 1 month ago

CBSE > Class 07 > Science

2 answers

Any Khan 6 years, 1 month ago

Yes of course

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Aaditya Agrawal 6 years, 1 month ago

Yes capillaries are very thin tubes which carry oxgen to every cell of human body

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A safety device which prevents damage to electrical circuit and possible fire

Posted by Palak Kinger 6 years, 1 month ago

CBSE > Class 07 > Science

2 answers

Any Khan 6 years, 1 month ago

Electric fuse

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Palak Kinger 6 years, 1 month ago

A safety device which prevents damage to electrical circuit and fires

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Chapter 6,7,8 book work

Posted by Gurjass Sandhu 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Gurjass Sandhu 6 years, 1 month ago

Chapter 6,7,8 complete home work

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Why the food chain is unidirection in nature?

Posted by Subhash Chand 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 1 month ago

The flow of energy in food chains is unidirectional. The energy which passes to the herbivores does not come back to the autotrophs. The energy that is captured by the autotrophs does not revert back to the Sun. Therefore, in the food chain, the energy moves progressively through various trophic levels. This energy is no longer available to the previous trophic level. Thus, the flow of energy in a food chain is unidirectional. The pesticides enter a food chain and subsequently get into our body by the following way: Pesticides are sprayed on the crop plants to protect them from the attack of pests. These pesticides when washed away into the soil or water bodies get absorbed by the plants. When plants are consumed as food by man or other animals, the pesticides enter the food chain. Since the pesticides are non-biodegradable, these chemicals get accumulated progressively and enter our body.

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What are the component s ofblood write the function s

Posted by Manasa M Manasa M 6 years, 1 month ago

CBSE > Class 07 > Science

3 answers

.. ... 6 years, 1 month ago

Blood carries(transports)oxygen from the lungs to different parts of body. It also carries digested food molecules from the small intestine to different parts of the body.It also transports hormones to the target organs,waste materials from various parts of the body (excretion organs like lungs,skin,kidney etc.) It regulates various function in the body. It helps to fight against disease germs.Blood helps to maintain our body temperature.

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.. ... 6 years, 1 month ago

Blood :-55% liqiud (plasma)-------->92%water and 8%dissolved plasma proteins:-Serum albumin,Serum globulin,serum fibrinogen and Lipoproteins------------------------------------------ 45%solid--------->Red blood cells (Erythrocytes),White blood cells(Leueoytes)Blood platelets(Thrombocytes)

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Pratiksha Chaudhary 6 years, 1 month ago

Of three types were used first platelets second RBC third BC IV plasma

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Write 6 to 7 method to prevent soil evparation

Posted by Satyam Mane 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 1 month ago

1] By doing afforestation ( Plantation down of trees ) 2] By planting crops with deep roots that will draw nutrients from deep in the earth and also bind the soil together. 3] Drain rain water run off properly. 4] By reducing tillage. 5] Allow grass to grow in plenty fields. 6] By avoiding overgrazing. Read more on Brainly.in - https://brainly.in/question/2414457#readmore

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What are the 2 effects of electric current

Posted by Harish Thiyagarajan 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Prakaash Prakaash 6 years, 1 month ago

Heat and light

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Name any two effects of electric current

Posted by Alok Ral 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Yogita Ingle 6 years, 1 month ago

The two effects of electric current are; heating effect and magnetic effect.

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What is adaptation

Posted by Alok Ral 6 years, 1 month ago

CBSE > Class 07 > Science

5 answers

Any Khan 6 years, 1 month ago

The features or characteristics of an organism which enable it to survive in its habitat are called adaptations ...??

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Home Stay 6 years, 1 month ago

The action or process of adapting or being adapted

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Yogita Ingle 6 years, 1 month ago

Animals and plants; living in such places; develop certain features which help them survive the harsh climate. To develop certain features in order to survive the given climate is called adaptation.

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Alok Ral 6 years, 1 month ago

1 ) Heatng effect 2) Magnetic effect

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Riya Sheemar 6 years, 1 month ago

A habbitat or area which has suitable conditions for animals to adapt

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Plz. Tell me about the blackhole because I have to explain it in the class.

Posted by .. ... 6 years, 1 month ago

CBSE > Class 07 > Science

2 answers

Yogita Ingle 6 years, 1 month ago

Black holes are one of the most mysterious and powerful forces in the universe. A black hole is where gravity has become so strong that nothing around it can escape, not even light. The mass of a black hole is so compact, or dense, that the force of gravity is too strong for even light to escape.

Black holes are truly invisible. We can't actually see black holes because they don't reflect light. Scientists know they exist by observing light and objects around black holes. Strange things happen around black holes to do with quantum physics and space time. This makes them a popular subject of science fiction stories even though they are very real.

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.. ... 6 years, 1 month ago

Sorry I by mistake change the subject. Actually I want it in hindi

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I will do my science subject learning of exercise

Posted by Akram Ahamad 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Pratiksha Chaudhary 6 years, 1 month ago

Yahi Mata Bata wali Kumawat Rahe

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What are the adaptation found in peguins ?

Posted by Archana Chandrakar 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Yogita Ingle 6 years, 1 month ago

Having black and white skin is a type of adaptation known as camouflaging. It is called counter-shading and makes it harder for both the predators and the prey to see penguins from all sorts of angles. The white chest of penguin protects them in the water by camouflaging them from being seen from below against the lighter sky coming through the waters surface. Their black backs help them blend in with the darker, deeper ocean waters below them, thus protecting them from their predators. They have thick layer of fat because it keeps them warm under such extreme cold conditions.

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How we can understand which rock is good for soil

Posted by Satyam Mane 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Yogita Ingle 6 years, 1 month ago

Soil contains humus, water, clay, sand and gravel.

The decaying dead matters in soil are called humus. Humus makes the soil fertile and provides nutrients to the plants.

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Define magic??

Posted by Aman Vats 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Home Stay 6 years, 1 month ago

The power of apparently influencing the course of events by using mysterious or supernatural forces

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What is perculation?

Posted by Aman Vats 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 1 month ago

In physics, chemistry and materials science, percolation (from Latin percōlāre, "to filter" or "trickle through") refers to the movement and filtering of fluids through porous materials.

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What is the use of plasma in our body

Posted by Satyark Kumar 6 years, 1 month ago

CBSE > Class 07 > Science

4 answers

Aman Vats 6 years, 1 month ago

A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light

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Aman Vats 6 years, 1 month ago

Along with water, plasma carries salts and enzymes. The primary purpose of plasma is to transport nutrients, hormones, and proteins to the parts of the body that need it. Cells also deposit their waste products into the plasma, and the plasma in turn helps remove this waste from the body.

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Aman Vats 6 years, 1 month ago

Plas

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Sunil Yadav 6 years, 1 month ago

What is the concave mirror

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How can soil useful for crops?

Posted by Ayushi Chaudhary 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Aman Vats 6 years, 1 month ago

Soil is useful for crops, because it gives nitrogen and water to crops for there groth.?

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Which gas is used for fighting against germs by white blood cells

Posted by Hareesha Bs 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Aman Vats 6 years, 1 month ago

Cells Use Bleach to Battle Bacteria. Scientists at the University of Otago, Christchurch have discovered that bleach is one of the key factors used by white blood cells to control bacterial infections in the body

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What is arobic respiration? Plz tell ans.

Posted by Anuja Lanjewar 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Akriti Mishra 6 years, 1 month ago

The the respiration in held the presence of oxygen is called aerobic respiration

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What will happened lf there are no platelets in the blood?

Posted by Hari Tk 6 years, 1 month ago

CBSE > Class 07 > Science

5 answers

Aman Vats 6 years, 1 month ago

Blood will overflow.

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Anuja Lanjewar 6 years, 1 month ago

The blood will be clot.

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Mayank Tiwari 6 years, 1 month ago

We will dead?????☠️☠️

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Vaishuu Choudhary 6 years, 1 month ago

Platelets is used in blood to clotting but if there are no platelets in blood the blood is not clotting and there are loss of blood

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Sharanyaa Mandal 6 years, 1 month ago

The blood will not be able to clot .

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The focal length of a mirror is 17cm .calculate its radius of curvature

Posted by Preeti Rajput 6 years, 1 month ago

CBSE > Class 07 > Science

2 answers

Sharanyaa Mandal 6 years, 1 month ago

34cm

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Yogita Ingle 6 years, 1 month ago

The relation between radius of curvature and focal length is given by
R = 2f
f = 15cm
R = 2(17) = 34cm

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When baking soda is mixed with lemon juice, Bubbles are formed with the evolution of a gas. What type of change it is? Explain.

Posted by Dhan Kumari Subba 6 years, 1 month ago

CBSE > Class 07 > Science

4 answers

Awanish Kumar 6 years, 1 month ago

Chemical change

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Vaishuu Choudhary 6 years, 1 month ago

Because of the carbondioxide and it's a chemical change because bubble are the new substance and chemical change means a change that form a new substance

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Yogita Ingle 6 years, 1 month ago

When baking soda is mixed with lemon juice, bubbles formed because of evolution of carbon dioxide gas. This is a chemical change, because in this reaction new substances are formed.

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Omm Night Hunter 6 years, 1 month ago

Chemical change

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Find out about blood group and their importance

Posted by Mohit Raj 6 years, 1 month ago

CBSE > Class 07 > Science

1 answers

Yogita Ingle 6 years, 1 month ago

Carl Landsteiner (1900) discovered that there are two types of antigens present on the plasma membrane of the RBC. These are antigen A and antigen B. These are also called corpuscle factors. There are also two types of antibodies present in the plasma. These are antibody A (Anti-A) and antibody B (Anti-B). These are also called plasma factors. The blood is classified into four groups on the basis of the presence or absence of these antigens. These groups are A, B, AB and O. This system of classification of blood is called: ‘ABO’ system.

The following table shows the types of blood groups and their antigens and antibodies:

Along with the A and B antigens or antibodies many people have another factor called the Rh factor. This is an antigen first found in Rhesus monkey (hence, called the Rh factor). People whose red blood cells contain the Rh antigen are said to be Rh positive (Rh+). People who lack it are called Rh negative (Rh-). A person with Rh blood does not have Rh antibody (which destroys Rh antigen) naturally. But, as and when an Rh antigen enters the blood, it develops and destroys the antigen.

If a person with blood group A has Rh antigen, his/her blood is said to be A+ (A positive). Similarly, if a person’s blood group is B and he/she do not have Rh antigen, then his/her blood group is B-(B negative). So, we have eight blood groups:

A+,B+,AB+,O+,A-,B-,AB- and O-

The following table gives a complete list of blood group matching: