Now we are going to discuss question number 21 till end. Okay, first of all i will read the question. Then we will discuss answer one by one and we will find the most suitable option understood now, question 21 in order to reduce your frictional forces with the environment whenever we use this word reduce, so you must use. Oiling. Oiling is the method by which you can reduce the friction. What is friction friction is a force that two surfaces exerts on each other when they rub against each other. It means when they are in contact, so they produce some friction surface pushing together. These are the factors rough versus small surfaces, small surfaces have low friction. Rough surfaces have higher friction lubricants, oil or grease. So if you apply lubricants or grease, you can reduce the friction. If you press forcefully high friction rough surfaces, high friction, press lightly, low, friction, smooth surface low, friction the real option. Bicyclists stand upright and wear white clothing. The standing position doesnt affect on friction so is wrong. Swimmers keep their arms wide open, uh wide open. It means there is no relation in this ss with because, if you minimize the friction, so you have to keep the streamlined body not wide open arms, so this is again wrong see we have to consider the fact that there is friction only with water, not with There no air, resistant and water resistant both are present in the environment d, speed, skaters, wear tight glossy clothes and keep their hand close to their bodies.

It means the position is different and glossy clothes. Obviously, this is for this minimize the friction. So i think d is correct e as well. The friction of a car with the air does not depend upon the shape of a car. No shape also affect the friction. So d is the most suitable answer because glossy the word glossy you can keep this thing in mind: glossy means greasy or uh some oiling. So this growth, this type of cloth, reduce the friction. Okay got it now. Move on question number two question: 22: paranesium is a unicellular organisms, with the shape of resembling the soul of a shoe. You can see this. This type of this organism is known as paramecium, and you can see this hair like structure. They are known as celia. Actually, i am talking about uni cellular organisms and some particular organ they have by me. They can move. So i would like to give this information first then we will read the question, so you can see this here like a structure. This is a unicellular organism. This is called paramecia, you can see in this picture euglena, and this claim i do not as well. This is also lg, and this is also planned, euglena and both have this this type of structure. This is known as flagella the green algae of microwave, the the it has two flagella. This is climato glass. It has one flagella. This is just like a thread like a structure, not real like a structure and another unicellular organism that is known as amipa.

The body of amoeba has finger likes projection which are called pseudopodia. These projections are called pseudopodia. Actually, pseudopodia is a finger like projection which help ameer to obtain food from surrounding. So these are locomotory organ or you can say these all can help to move these plants and uh animals. This todopodia is for amoeba flagella and this flagella also for chlamydia loss. This is for euglena, and this air, like instructor, that is called celia, is for paramecium or paramecium. Both are correct, so read the question and find the answer which one of the following uses: celia for moving. You can see euglena no amoeba, no paramecium, yes, euglena yeah world wars, no influenza virus virus. No, so answer c is correct. Now more question number 23, which what is it true about shadows formation? We have uh know this thing that light cannot pass through or peak or of big objects, so only opaque or little bit. Translucent object can form shadow. So when an object is transparent, obviously this one transparent, it will form a shadow only if much larger than the light source transparent, no light pass through the transparent thing it doesnt form any shadow. So a is incorrect. An object will form a shadow only if it is large enough no size does it depend. An object will form a shadow. It is opaque, it is correct, see again you read d as well. If an object is transparent, it will form a shadow regardless of what shape and size no transparent object.

Dont make any shadow. An object will form a shadow only if it is in the air. No, it is incorrect, so answer c, opaque, uh. An object will form a shadow if it is opaque c is correct. Number one question number 24 question number 24, its all about another type of invertebrate. Actually there are nine phylum of invertebrates and Music in another video. We will discuss one by one, but in this case you just read the question. Then i will uh tell a little bit about all options, so you will be able to find the correct option which of the following sale and trades can be found in the and traits are those organisms. They have cylindrical bodies. They have one mouth on which all Music, just like jellyfish all tentacles can be appeared, so coral, jellyfish and sea animal are cilian. Trees. Sponges are sponges, belong to phylum polyphera, actually, sponges have pores in their bodies. Have you seen this spongebob? It lives in sea? It lives, but it has pores. Syrian trees are those organisms they dont have any pores in their body, so sponges is incorrect. Coral is correct because coral is sealant rate worms, worms found in mud, earth form and other worms found in water as well. But worms are not saline trees, they belong to another phylum mollusk, they form another, they have no pores, they have shell. This is another orthoports autoports have different structure. They have so they have they dont.

They cannot be found in c, so coral is only salient rate in this picture. So just read the answer: electric invertebrate animal of a phylum that includes jellyfish, coral and sea animal. So you re, you just keep all three names when cilian trades comes in the question, so you, if jellyfish, coral and sea animal, is there. So this is the correct answer. Just keep this information in your mind. If we have times, we will discuss in detail all nine five phylum about invertebrate, now, question number: twenty five, which of the following statement is true about the electric current. Only electric current only uh the produce when the circuit is closed and it contain an electric battery. Just read the option, then we will find the answer it is produced only if the circuit is closed and contains an electric battery b. It represent the quadratic moment of electron through conductor. No, it represents an ordered movement of proton. No, it actually electron are moving during electric current. The proton then proton is incorrect. It is measured with ammeter uh mounted in series with the battery when the circuit is open. Ammeter, obviously measured current, but the circuit is closed. It has the same value, no matter how many circuits elements are connected to the battery circuit. No current would be changed, so a is more suitable answer. It is produced only if the circuit is closed and contain an electric battery. Now question number 26 pollen grain are formed in we have discussed the flower diagram.

Flower has four structures: supple battle, stamin and carpal. Sepal are green in color; they just save or protect the flower and petals are colorful, they attract petals and stamen has two type or two structural filament and enter in enter. You can see pollen green and then carpal uh style stigma ovary over containing ovule, so pollen green are formed in stamin. Pollen brain in anther and anther is a part of a stamina. So e is correct. Now, question 27: regarding the flatware we have discussed, flatware fragmenter always formed an image that is virtual. That is same in size. Just read the answer. It reflects right, diffusely diffusely means it absorbs something. It forms the image of the object situated behind it. The image of an object is formed at distance equal to half the distance between the mirror and the object. Half no same distance. It forms a bright virtual image equal to the size of the object. It forms upright real image equal to the size of the object. No, it doesnt form real image. It is. The image is virtual, so d is correct. Now, question number 28: the part of the flour which produces the seeds after fertilization and excel the style. The plant ovary the stigma, the anther, the part of the flower which produces seeds after fertilization, uh plant ovary and excel after obviously after fertilization, excel uh stigma. Sigma style ovary is the part. Okay question number 27. Regarding the flattener, we can see that it reflects light.

Diffusely inside by the spreading no – and it forms an imagery object situated behind it and now in front of the image of an object, is formed at a distance equal to half. No, it forms upright virtual image equal to the size of the object, correct. It forms upright real image. No, no real number is formed. It forms now question 28. The part of the flower which produces the seed after fertilization is the egg cell, not the stigma and third style in the plant ovary in ovary. There is excel so excel diffuses or excel meet the male gamete and seeds produce in excel. So a is correct. Now question 29: ah meteor is the same as meteorite is a small body made up of a stone or metal obtaining outside the earth? It is meteorite that has reached the surface of the earth d due to the friction with the terrestrial atmosphere it burns completely before it reaches the surface of the earth. E is the same as meteorite. Just read the information when meteorites enters the earth, atmosphere or other planet at high speed and burns up, the fireballs or shooting stars are called matures when a meteorite survive or trip through atmosphere and hits the ground it is called meteorite. So it burned up due to friction the terrestrial atmosphere it burns completely before it reaches the surface of the earth. So d is correct. Answer now last question: question number 30: when light beam falls on the windshield of a car, so what happened? Light always travels in straight line until something gets in its way.

When that happens, lights can be absorbed, reflected or refracted bent. Depending on what kind of surface it hits a simple definition of light transmission is, when light travels through a medium, such as glass, without being reflected, absorbed or scattered. You can see this diagram as well reflect transmit some absorb, or maybe scatter so windshield of a car. So the light is fully reflected, no its, not a mirror uh. The light cannot be absorbed because windshield is not black uh not be absorbed. Some some light can be absorbed its not a black. Obviously, when she is not applied, a light is transmitted through the windshield. Only if there is passenger in the car, passengers, emission or transmission of light doesnt depend on presence of passengers d. The light phenomena of reflection, transmission and absorption occur simultaneously. Only light reflection, transmission phenomena occur simultaneously, actually a light can be absorbed, transmit and scatter windshield when it light beam falls on windshield. So all these happen, reflection, transmission and absorption. So d is correct, so this was all about 30 questions of paper 2020 for benchmark level. So if you have any uh problem or queries, so you can ask me – and this is all about – we have done till 30 questions. Thank you very much next lesson. We will start paper 19..