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Ask QuestionPosted by Anushika Singhal 5 years ago
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Yogita Ingle 5 years ago
At normal temperature, the surface of copper is covered with copper oxide. The thin layer of copper oxide is a protective cover which protects copper from further oxidation. Thus this copper oxide does not burn as it is already reacted with the oxygen in the air. No further oxidation can occur.
Yashika B. 5 years ago
Posted by Sameer Kumar 5 years ago
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Aditya Prakash Purohit 5 years ago
Yogita Ingle 5 years ago
When starlight enters earth's atmosphere it undergoes multiple refraction continuously before it reaches the earth. Because of the increasing refractive index, the starlight bends downwards (ie towards the normal) and thereby the apparent position of the star is slightly higher than its actual position.
Posted by Abhinav Yadav 5 years ago
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Posted by Aastha Aarya 5 years ago
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Meghna Thapar 4 years, 11 months ago
Double displacement reactions may be defined as the chemical reactions in which one component each of both the reacting molecules is exchanged to form the products. During this reaction, the cations and anions of two different compounds switch places, forming two entirely different compounds.
The general equation which represents a double displacement reaction can be written as:
Double displacement reactions generally take place in aqueous solutions in which the ions precipitate and there is an exchange of ions.
For example, on mixing a solution of barium chloride with sodium sulphate, a white precipitate of barium sulphate is immediately formed. These reactions are ionic in nature. The reactants changes into ions when dissolved in water and there is an exchange of ions in solution. This results in the formation of product molecule.
Posted by Arpita .9 5 years ago
- 2 answers
Yashika B. 5 years ago
Yogita Ingle 5 years ago
- Armature Core: Holds the armature coil in place and provides mechanical support.
- Armature Coil: It helps the motor to run.
Posted by Dharmin Sanghvi 5 years ago
- 4 answers
Kiran Kumari 5 years ago
Manvi Singh 5 years ago
Yogita Ingle 5 years ago
Metallic oxides: A chemical compound formed by metal and oxygen.
Examples:
- Magnesium reacts with oxygen to form magnesium oxide
2Mg + 2O2→ 2MgO
- Other examples of metallic oxides – Na2O, Al2O3, FeO, CuO, V2O5
Posted by Prawash Priyam 5 years ago
- 4 answers
Gaurav Seth 5 years ago
Considering the loss of classroom teaching time due to the Covid-19 pandemic and lockdown, CBSE reduced the syllabus of classes 9 to 12 with the help of suggestions from NCERT.
The CBSE syllabus has been rationalized keeping intact the learning outcomes so that the core concepts of students can be retained.
Deleted syllabus of CBSE Class 10 Science
Posted by Aditya Singh 5 years ago
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Posted by Shiwani Kumari 5 years ago
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Gaurav Seth 5 years ago
Magnification of Convex Lens:
It is a ratio between the image height and object height. A magnification of 2 indicates the image is twice the size of the object and a magnification of 1 indicates an image size being the same as the object size. If the magnification is positive, then the image is upright compared to the object (virtual image). If magnification is negative then the image is inverted as compared to the object (real image).
Posted by Ritesh Yadav 5 years ago
- 1 answers
Yogita Ingle 5 years ago
All organic compounds are derivatives of hydrocarbons.
The derivatives are obtained by replacing one or more hydrogen atoms with some other atom or a group
of atoms.
The new set of compounds formed after replacement has functions different from the parent hydrocarbon.
Functional group:
An atom or a group of atoms present in the molecules, which determines the characteristics property of the organic compounds, is called the functional group.
Posted by Rohit Kukreja 5 years ago
- 1 answers
Gaurav Seth 5 years ago
Apparatus: A battery (12 V), a variable resistance for a rheostat), an ammeter (0-5 A), a plug key, and a long straight thick copper wire. Procedure: Fix the cardboard and insert the wire through the centre of cardboard such that it is normal to its plane. Connect the wire with rheostat, ammeter, battery and plug key in series Sprinkle the iron filings uniformly on the cardboard. Keep the variable of the rheostat at a fixed position and note the current through the ammeter. Close the key and gently tap the cardboard. Observe the pattern of the iron filings over the cardboard.
The magnetic field lines are formed in concentric circles around the current carrying conductor and whose centre lies on the wire. These lines do not intersect each other and are equidistant from each other. 1. Right hand thumb rule II. Since alpha particles are positively charged so a magnetic field will be produced. But neutrons are neutral charge so no magnetic field is produced.
Posted by Siddharth Upadhyay 5 years ago
- 1 answers
Gaurav Seth 5 years ago
The first trophic level in any food chain is of producers which are green plants. They capture sunlight and convert solar energy into chemical energy. This energy is then transferred to other organisms as they feed on producers. The energy transferred from one trophic level follows 10 per cent law according to which only 10% of the energy is transferred from one trophic level to subsequent higher trophic level. Thus this energy is in the form of chemical energy.
Posted by Venom Stryker 5 years ago
- 4 answers
Siddharth Upadhyay 5 years ago
Yogita Ingle 5 years ago
An ammeter is a device (instrument) used for measuring large electric currents in ‘ circuits. For this purpose, it is put in series with the circuit in which the current is to be measured.
For accurate measurement, an ammeter must have following two properties:
- A very small resistance (zero in ideal case).
- A very large current carrying capacity.
It is done by connecting low resistance in parallel with the coil of the galvanometer. This parallel low resistance is called shunt. The shunt reduces the overall resistance of the ammeter and increases its current carrying capacity.
Posted by Chakshuta Patidar 5 years ago
- 1 answers
Aziz Fatima 4 years, 11 months ago
Posted by Vaishnavi Patil 5 years ago
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Gaurav Seth 5 years ago
roasting
Sulphide ores are transformed into oxides by the process of roasting. In this process, concentrated ore is heated in the presence of surplus air. Example: Zinc blende, ZnS, a sulphide ore of zinc, is roasted in the presence of air. Onroasting, zinc sulphide gets transformed into zinc oxide.
Posted by Harshit Girase 5 years ago
- 2 answers
King?Adithya H. M.. 5 years ago
Gaurav Seth 5 years ago
Mendel demonstrated that traits can be either dominant or recessive through his monohybrid cross. He crossed true-breeding tall (TT) and dwarf (tt) pea plants. The seeds formed after fertilisation were grown and the plants that were formed represent the first filial or F1 generation. All the F1 plants obtained were tall. Then, Mendel self-pollinated the F1 plants and observed that all plants obtained in the F2 generation were not tall. Instead, one-fourth of the F2 plants were short. From this experiment, Mendel concluded that the F1 tall plants were not true breeding; they were carrying traits of both short height and tall height. They appeared tall only because the tall trait was dominant over the dwarf trait. This shows that traits may be dominant or recessive.
Posted by Mungi Rajesh 5 years ago
- 1 answers
Yogita Ingle 5 years ago
Dwarfs - Smaller stars are called dwarf stars. Red and yellow stars are generally called dwarfs. A brown dwarf is one that never quite got large enough for nuclear fusion to occur. A white dwarf is the remnants of the collapse of a red giant star.
Posted by Sikha Oram 5 years ago
- 3 answers
King?Adithya H. M.. 5 years ago
Yogita Ingle 5 years ago
Yes it will. Even if half of the convex lens is covered with black paper, the lens will produce a complete image. however the intensity of the image may be less. It can be observed experimentally by using a lighted candle and a convex lens.
Experiment -
1. Take a lighted candle and place it in front of a convex lens mounted on a plane surface.
2. Move the candle along the axis of the plane to obtain the full image on the screen. Once the full image is observed, mark the position of the candle without moving it.
3. Now cover the lower exact half of the lens with a black opaque paper. Do not change the position of the candle.
4. At this point, you will observe a full image of the candle, but you will find that the intensity is reduced. This is because the covered part of the lens does not allow light to pass through it. So the amount of light reaching the screen is reduced.
Diagram -
Posted by Anand Chandravanshi 5 years ago
- 2 answers
King?Adithya H. M.. 2 years, 1 month ago
Yogita Ingle 5 years ago
Following are a few advantages of the heating effect of current:
1)The heating effect of current is used in heating appliances such as electric iron, room heaters and water heaters.
2) An electric fuse is an important application of the heating effect of current. The working principle of the fuse is based on the heating effect of current.
3) They are also utilised in electric bulbs and electric lamps to produce light.
Following are the disadvantages of the heating effect of current:
1) When an electric current flows through the conductor, a part of it is converted into heat energy. This is a waste of energy.
2) The heat produced can damage the insulation and other electrical components, or even cause a fire
3) Reduces the life of several components in the circuit
4) An additional cooling system needs to be added to the circuit to counter the heating effect. This adds to the cost.
Posted by Rahul Yadav 5 years ago
- 2 answers
Yogita Ingle 5 years ago
The potential difference between two points is said to be 1 volt if 1 joule of work is done in moving 1 coulomb of electric charge from one point to another.
Dinesh Jogala98 5 years ago
Posted by Junaid Ahmad 5 years ago
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Posted by Ranvijay Kumar 5 years ago
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Zaid Rahman 5 years ago
Posted by Ranvijay Kumar 5 years ago
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Posted by Ranvijay Kumar 5 years ago
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Priyanka Battise 5 years ago
Posted by Mangal Singh Panwar 5 years ago
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Faizan Hussain 5 years ago
Navjot Kaur 5 years ago
Posted by Ranvijay Kumar 5 years ago
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Faizan Hussain 5 years ago
Navjot Kaur 5 years ago
Posted by Naman Bandawala 5 years ago
- 2 answers
Jaat Shab 5 years ago
Gaurav Seth 5 years ago
Law of independent assortment is based on dihybrid cross. It states that inheritance of one character is always independent of the inheritance of other characters within the same individual. In other words, if the inheritance of more than one character is studied simultaneously, the factors or genes for each character assort out independently to the other gene or factor.
A good example of independent assortment is Mendelian dihybrid cross. The presence of new combinations - round green and wrinkled yellow, suggests that the genes for the shape of the seed and color of the seed are assorted independently.
Posted by Shriyansh Sharma 5 years ago
- 3 answers
Gaurav Seth 5 years ago
When the light rays passes through the atmosphere having layers of different densities and refractive indices, then atmospheric refractioon takes place. The actual sunrise takes place when the sun is above horizon. When the sun is just below the horizon, the light rays coming from it , on entring the Earth's atmosphere suffer atmospheric refraction from a rarer to denser medium . so, they bend towards the normal at each refraction. Due to continuous refraction of light rays at each layer, it follows a curved path and reaches the eye of the observer. As a result , we can see the sun 2 mins. before it rises above the horizon in the morning .
It is also due to refraction that we can still see the sun for abt 2 mins. even after the sun has set below the horizon.
As a result, the time from sunrise to sunset is increased by abt 4 mins.
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King?Adithya H. M.. 5 years ago
1Thank You