InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 7901. |
The calorific value of hydrogen is 1,50,000 Kj//Kg and that of LPG is 55,000 KJ//Kg. Which among the above is a good fuel? |
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| 7902. |
To study the dependence of current (I) on the potential difference (V) across a resistor, the following observations were made by four students A, B, C and D. The teacher found that one of the students has made wrong observations. The student who made the mistake is : |
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Answer» A |
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| 7903. |
Define specific resistance electrical conductivity ? Give its unit. |
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Answer» Solution :The reciprocal of electrical RESISTIVITY of amaterial is called its electrical conductivity. `sigma=1/(rho)` ITD unit is `"ohm"^(-1)"metre"^(-1)`. It is also represented as NHO `"metre"^(-1)`. |
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| 7904. |
What is Narmada Bachao Andolan ? |
| Answer» Solution :Narmda Bachao ANDOLAN (SAVETHE Narmada Movement ) is a movement to protest aboutthe height ofSardar SARDAR Sarovar Dam on the RIVER Narmada , thereby criticising LARGE dams for addressing problems. | |
| 7905. |
Definethetime evolution. " Evolutioncannotbe equatedwithprogress. " Giveexamples to justifythisstatement. |
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Answer» Solution :Evolutionisdefined as " thegradual unfoldingofevents bywhichnew organismsevolved frompreexistingorgaismsthroughchangessince THEBEGINNINGOF LIFE". Thereisno realprogress in the ideaofevolution.Itissimply the generationofdiversityandtheshapingof diversitybyenvironmentalselection. Theonlyprogressivetrend inevolutionseemsto bethatmoreandmorecomplex bodydesighshveemergedover time.However, again itisnotasif theolderdesignsareinefficient.Manyof theolderandsimplerdesignsstill survive. FOREXAMPLE, one ofthesimplestlifeforms,bacteria,inhabit the mostinhospitablehabitats likehotsprings,deep SEA thermalventsandthe icein ANTARCTICA. |
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| 7906. |
Draw a ray diagram to show the image formed by a convex lens when the object is placed between F and 2F. |
Answer» Solution :(i) Ray diagram for object placed between F and 2F  (II) ONE calorie is defined as the amount of heat ENERGY required to rise the TEMPERATURE of 1 gram of water through `1^@C`. |
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| 7907. |
________ was the first chairman of Indian Atomic Energy Commission. |
| Answer» SOLUTION :DR. HOMI JAHANGIR BHABA | |
| 7908. |
The animals which give birth to young ones are |
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Answer» oviparous |
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| 7909. |
Which power has more penetrating power? |
| Answer» Solution :`gamma` rays | |
| 7911. |
Is there any relationship of latent heat with the regelation? |
| Answer» Solution :Latent heat required to MELT layer of ICE is PROVIDED by the metal WIRE and heat GIVEN off on re-freezing of ice is conducted through wire. | |
| 7912. |
The potential difference generated across a solar cell is independent of its area. |
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| 7913. |
There are 10000 turns in a trànsformer. Voltage in the primary is 0.2A. The transformer is wound so as to get a current 0.4A in the secondary. What is the maximum output power that received from this transformer? |
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| 7914. |
State the relation between work, charge and potential difference for an electric circuit. Calculate the potential difference between the two terminals of the battery if 100 joules of work is required to transfer 20 coulombs of charge from one terminal of the battery to the other. |
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Answer» Solution :1 volt is the POTENTIAL diffe.rence between two points in a current carrying CONDUCTOR wh.en 1 joule of work is done to move a charge of 1 coulomb from one point to ANOTHER. Potential difference `=("Work done" (W))/("Charge TRANSFERRED "(Q))` `(100 j)/(20 C)` = 5 V |
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| 7915. |
An object is kept in front of a concave mirror of focal length of 15cm image formed is 3 times the size of the object. Calculate the two possible distances of the object from the mirror. |
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Answer» SOLUTION :Case (1) Image is real. M=-3 Here f=-15cm Now m=-v/u=-3 Or, V=3u From the mirror formula 1/f=1/u+1/v -1/15=1/u+1/3u Distance of the object U=-20cm Case (2). When the image is virtual m=3 Now m=-v/u=3 or, V=-3 From the mirror formula 1/f=1/u+1/v Then -1/15=1/u-1/3u 2/3u=-1/15 Distance of the object U=-10cm |
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| 7916. |
Parts of flower with accessory and essential whorls. |
Answer» SOLUTION : 
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| 7917. |
Whatare magneticfield lines ? |
| Answer» Solution :A magnetif FIELD line is the PATH alongwhichnorth POLE ofa magneticcompass needle points . | |
| 7918. |
Insidea bar magnet the directionof the magneticfieldlines is….. . |
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Answer» from N-poleto S-POLE of THEMAGNET |
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| 7919. |
Movement against tobacco: Tata trust: Education of slum children :____________ |
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| 7920. |
What is drift speed ? |
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Answer» Solution :ELECTRONS in the conductor move with a constant AVERAGE speed which is known as drifrt speed or drift velocity. `"Drift velocity"V_(d)=(1)/(nqA)` Where, I = Electric current n = NUMBER of charges q = magnitude of electric CHARGE A = Area of cross section of the conductor |
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| 7921. |
Which precautions would you take during those disasters? |
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Answer» Solution :The disasters SHOWN in the pictures and the steps to be taken to minimise the effect of the disaster are as follows: i. PICTURE A shows earthquake. ii. Picture B shows a house on fire. Steps to be take during a fire disaster are as follows: a. Use fire extinguisher to put off the fire. b. Run towards a safe place away from the location of fire. c. While entering to the safe room, make sure that thereis no fire in the that room. You can do so by touching the door and feeling the HEAT on door before opening it. d. If there is lot of smoke, keep your head low to the ground to avoidexcess inhalation of smoke. e. Call the fire brigade immediately. f. Also, if any person has suffered minor burns, 1. Wash the injured part with water or hold it under water. Clean the wound with an antiseptic solution using a cotton swab and apply ointments that are specially prescribed for bruns. 3. Cover the would using dry dressing. If a person has suffered major burns, 1. use sterilized cloth to cover the wound. Immediately REMOVE jewellery, shoes, etc., from the body. 3. Do not touch or burst the blisters on the skin, remove the cloth stuck to the region of burnt skin. iii. Picture C shows a snake bitting a person. |
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| 7922. |
How can we trace a current-carrying wire hidden in a wall? |
| Answer» Solution :A current-carrying WIRE hidden in a wall can be DETECTED using a compass needle . If the MAGNETIC needle is moved along the wall, it DEFLECTS if a current-carrying wire is hidden inside it . | |
| 7923. |
Ina quarry of sandstone, a digger found some bones below the rocks. He took them out and was about to throw them away when his fellow digger told him that this could be a fossil and they should hand it over to the museum. Answer the following questions based on the above situation: (i) Which values are promoted by the fellow digger? (ii) What contributions are the diggers making to the scientific world? (iii) Imagine yourself to be the person in the museum whom the diggers approach. What would be your response to the diggers' discovery? |
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Answer» Solution :(i) Rational thinking, awareness, PRESERVATION of HERITAGE. (ii) They provided a link which can help scientists to STUDY the PROCESS of evolution and KNOW more about the world in which humans did not exist. (iii) I would take the bones samples and send them for carbon dating to find which period they belong to. |
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| 7924. |
Explain series and parallel circuit. |
Answer» SOLUTION :
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| 7925. |
Watt |
| Answer» SOLUTION : It is defined as a derived UNIT of 1 JOULE per second, and is used to QUANTIFY the rate of ENERGY transfer. | |
| 7926. |
State and prove parallel axis theorem. |
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Answer» SOLUTION : Parallel axis theorem : The moment of inertia of a rigid body about an axis passing through a point is the sum of moment of inertia about parallel axis passing through centre of mass `(I_G)` and mass of the body multiplied by square of distance`(MR^2)`between the axes i.e., `I = I_G + MR^2` Proof : Consider a rigid body of mass M with 'G' as its centre of mass. `I_G`the moment of inertia about an axis passing through centre of mass. I = The moment of inertia about an axis passing through the point 'O 'in that plane. Let perpendicular distance between the axes is OG = R (say) Consider point P in the given plane. Join OP and GP. Extend the line OG and drop a normal from 'P' on to it as shown in figure.  The moment of inertia about the axis passing through centre of mass G. `(I_G) = Sigma m GP^2 "" ....(1)` M.O.I of the body about an axis passing through O (I) `= Sigma mOP^2 "" ...(2)` From triangle OPD `OP^2 = OD^2 + DP^2` `RARR OD = OG +GD` `therefore OD^2 = (OG +GD)^2 = OG^2 + GD^2 + 2OG, GD ""...(3)` From equations (2) and (3) ` I = Sigmam OP^2 = Sigma m [(OG^2 + GD^2 + 2OG . GD)+ DP^2]` `therefore I = Sigma m {GD^2 + DP^2 + OG^2 + 2OG . GN}` But ` GD^2 + DP^2 = GP^2` `therefore I = Sigma m { GP^2 + OG^2 + 2OG . GP}` `therefore I = Sigma m GP^2 + Sigma m OG^2 + 2OG Sigma mGD "" ....(4)` But the terms `Sigma mGP^2 = I_G` `Sigma mOG^2 = MR^2 (becuase Sigmam = " M and OG = R)` The term `2OG Sigma mGD` = 0 , Because it REPRESENT sum of moment of masses about centre of mass . Hence its VALUE is zero . ` therefore I = I_G +MR^2` Hence parallel axis theorem is proved . |
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| 7927. |
It is possible to produce energy from mW to MW using solar photovoltaic cells |
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Answer» Solution :(i) A silicon solar cell of dimension 1 `cm^2` generates a current of about 30 mA and potential difference of about 0.5 V. Thus a silicon solar cell of dimension 100 `cm^2` will generate about 3 A `(30 mA // cm^2 XX 100 cm^2 = 3000 mA)` current and 0.5 V. (ii) If solar cells are connected in series the potential difference gets added but current remains the same. If solar cells are connected in PARALLEL the potential difference remains the same but the current generated is the SUMMATION of current from individual cells. (iii) By using this principle we can obtain power of desired QUANTITY. (iv) We can decide the number of solar panels to be used and what type of combination we can have to get required amount of electric power. (v) Hence, solar photovoltaic cells can be used to obtain mW to MW power. |
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| 7928. |
How can the oil spills on waters of rivers and oceans be cleaned? |
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Answer» Solution :(1) By USING mechanical means, the crude oil spills can be removed, but this is very difficult. (2) The BIOLOGICAL way to remove this pollution is done by using culture of microbes like Pseudomonas spp. and Alcanovorax borkumensis. (3) They have the ability to DESTROY the pyridines and other chemicals present in the hydrocarbons. (4) They are therefore released at the place of the oil spills to clear them. (5) These bacteria are called hydrocarbonoclastic bacteria (HCB) which decompose the hydrocarbons and bring about the reaction of carbon with oxygen. In the process `CO_2` and water are formed. In this way, the oil spills are cleaned. |
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| 7929. |
You must have reead the newa about many deaths due to poisonous liquor. Why does it happen ? |
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Answer» Solution :a. Liquor is produced by fermentation of substances such as yeast. b.If this fermentation PROCESS is incomplete or not performed correctly, poisonous liquor is produced. c. CONSUMPTION of EVEN small quantity of such poisonous liquor may PROVE fatal. |
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| 7930. |
Two lamps rated 100W,220V and 25W,220V are connected in parallel to 220V supply. Calculate the total current through the circuit. |
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Answer» Solution :In parallel grouping VOLTAGE remains same across each LAMP. Hence, currents `I_1 and I_2` flowing through 2 lamps are: `I_1=P_1/V=100/220=5/11 A` and `I_2=P_2/V=25/220=5/44 A` `THEREFORE` Total CURRENT `I=I_1+I_2=5/11+5/44=(20+5)/44=25/44 A` |
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| 7931. |
What is a solenoid? Discuss the magnetic fielddue to a current - carryingsolenoid . |
| Answer» Solution :SOLENOID: A coilof MANY circular turns of INSULATED copperwire wrapped closely in the shape of cylinder is called solenoid . | |
| 7932. |
It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm. (i) What should be the range of distance of an object placed in front of mirror ? (ii) Will the image be smaller or large than the object ? Draw a ray diagram to show the formation of image in this case. (iii) Where will the image of this object be, if it is placed 24 cm in front of the mirror ? Draw a ray diagram for this situation also to justifyyour answer. Show the positions of the pole, the principal focus and the centre of curvature in the above ray diagrams. |
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Answer» Solution :In a concave mirror an erect image will be OBTAINED when the object is placed between pole and focus of the mirror. Focal length, f = 12 cm (i) Therefore, the range of object DISTANCE is between 0 cm to lt12 cm (from zero to less than 12 cm). (II) Image formed will be MAGNIFIED, i.e., large than the object. (III) If the object is placed at 24 cm in front of the mirror, it means that object is placed at 2f, i.e., at the centre of curvature (at C) of the mirror.  The real, inverted and same size (of the object) imagewill also be formed at 24 cm. 
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| 7933. |
Mention the kind of lens that can form: (i) Real, inverted and magnified image (ii) Virtual, erect and magnified image (iii) Real, inverted and diminished image (iv) Virutal, erect and diminished image. |
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Answer» SOLUTION :(i)Convex lens (ii) Convex lens (III) Convex lens (iv) Concave lens. |
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| 7934. |
Find out the reading of ammeter and voltmeter In the circuit given below : |
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Answer» Solution : EQUIVALENT RESISTANCE R = (2 + 3 + 3 + 4) `Omega` `=12 Omega` Total current DRAWN = Ammeter reading = `(V)/(R)` `=(6)/(12)=0.5 A ` Voltmeter reading =`IR_(1)=0.5xx2=1V` |
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| 7935. |
State laws of reflection of light. |
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Answer» Solution :The laws of REFLECTION are : (i) The ANGLE of incidence is EQUAL to the angle of reflection. (ii) The incident ray, the reflected ray, and the NORMAL at the point of incidence all LIE in the same plane. |
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| 7936. |
At what speed should a source of sound move away from a stationary observer so that observer finds the apparent frequency equal to half of the original frequency? |
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Answer» SOLUTION :When the source is moving away from the stationary listener, the expression for the APPARENT frequency is `n.=((v)/(v+v_(s)))n` `(n)/(2)=((v)/(v+v_(s)))n` `v_(s)=v` |
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| 7937. |
The radius of curvature ofa spherical mirror is 20 cm. What is its focal length? |
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Answer» SOLUTION :Radius of curvature `R=20` CM Radius of curvature of a SPHERICAL MIRROR `=2xx` focal length (f) `R=2f` `f=R/2=20/2=10cm` Hence the focal length of the given spherical mirror is 10 cm. |
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| 7938. |
Which type of retinal cells respond to brightness of light ? |
| Answer» SOLUTION :The ROD SHAPED cells respond to brightness//intensity of LIGHT. | |
| 7939. |
Name the different colours of light in the proper sequence in the spectrum of light. |
| Answer» Solution :In spectrum these COLOURS APPEAR in the following ORDER : Violet , indigo blue , green, yellow, ORANGE and RED. | |
| 7940. |
a) State in brief the function of the following organs in the human female reproductive system. Ovary, fallopian tube, uterus (b) Why mensuration take place ? |
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Answer» Solution :Funtion of follopion tube : (i) Producation of female gamete. (ii) Producation of female hormone Function of follopian tube: (i) Site of fertilization (ii) Transfer of female gamets from ovary Function of UTERUS: (i) Iinplantation of zygote fertilizes the egg. (ii) Nourishment to the developing embryo Menstruation : It is the periodic breakdown of uterine lining and it is removed ALONG with BLOOD & mucous in human female uterine lining is required to nourish the embryo that is FORMED if fertilization takes place. In absence of fertilization the lining is not requirea and hence is shed in the from of menstruation. |
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| 7941. |
Some residents of your colony are planning to cut trees to create a place for parking vehicles. You are upset by knowing all this and wanted to do something to create awareness about the importance of trees. (i) List any three reasons that you will use to convince residents of your colony not to cut the existing trees. (ii) List any three values that would be inculcated amongst them with such approach. |
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Answer» Solution :(i) Importance of GREEN plants, reducing AIR pollution, reducing NOISE levels, aesthetic value, sapling distribution, giving potted plants in place of bouquet, CREATING awareness. (ii) To protect and improve the natural ENVIRONMENT, social awareness, environmental conservation, eco-friendly approach value for life. |
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| 7942. |
A ball of mass 05 kg slows down from a speed of 5 m s^(-1) to that of 3 m s^(-1) . Calculate the change in the kinetic energy of the ball. |
| Answer» SOLUTION :4 J (DECREASE) | |
| 7943. |
In which of the followingcases is no currentinduced in the loop ? |
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Answer» The loop is moved in the DIRECTION of the MAGNET |
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| 7944. |
Give reason for thefollowing : Why are copper and aluminium wires usedas connecting wires ? |
| Answer» Solution :These are good CONDUCTORS of electricity/LOW RESISTANCE, low resistivity. | |
| 7945. |
In hydroelectric power plant, the _____________ energy of the flowing water drives the turbine. |
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Answer» CHEMICAL |
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| 7946. |
Give an example of indirect harnessing of solar energy . |
| Answer» Solution :All green plants prepare CARBOHYDRATES from carbon dioxide and water in the presence of SUNLIGHT by the process of photosynthesis. All non - green plants and ANIMALS directly or indirectly consume food from the green plants (PRODUCERS) and store this food in their bodies in the formof chemical energy . In other WORDS, solar energy is transformed into chemical energy. | |
| 7947. |
On what factors does the resistance of a conductor depend? |
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Answer» Solution :RESISTANCE of a conductor depends on: 1] Nature of the material `[RHO]` 2] LENGTH of the wire[i]. 3]AREA of cross-section of the wire [A]. 4] Temperature |
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| 7948. |
Can a freely suspended cunent carrying solenoid stay in any direction ? Justify your answer. What will happen when the direction of cunent in the solenoid is reversed ? Explain. |
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Answer» Solution :A CURRENT carrying solenoid behaves like a magnet. When suspended FREELY, it will STAY in north-south DIRECTION. On REVERSING current its polarity will be reversed and so it will turn at `180^(@)`. |
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| 7949. |
What is the kind of mirror used by an ENT specialist to examine the ears of a patient ? |
| Answer» Solution :A CONCAVE mirror GIVES an enlarged VIEW of the EAR, nose or throat. | |
| 7950. |
While boating with parents, a child saw a beautiful fish in the lake. He tried to catch it, thinking that it is very close to the boat. His parents told him that the fishes are deep in water and he should not try to catch them. But he did not listen to them and the situation became worse when he fell in the lake instead of catching it. Answer the following questions based on the situation given above. (i) Why did the fish appear close to the boat when in actual it was deep in water? (ii) What values are neglected by the child? |
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Answer» Solution :(i) This is due to the phenomenon of refraction. Light reflected from the fish travels through the water towards the eye. As it PASSES from the water into the air, it refracts away from the normal because water is DENSER than air and THUS, the fish appears closer. (ii) Obeying elders, being CAREFUL, understanding REASONS for natural phenomena. |
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