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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.
| 1651. |
The resistance offered by a wire of unit length and unit cross-sectional area is called resistivity. For a material irrespective of length and area, the resistivity is constant. It is also called specific resistance of the material. Metals and alloys have low resistivity while insulators have high resistivity. Resistivity of two elements A and B are 1.62 xx 10^(-8) Omega m and 520 xx10^(-8) Omega m respectively. Out of these two, name the element that can be used to make : (i) filament of electric bulb. (ii) wires for electrical transmission lines. |
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Answer» Solution :(i) ELEMENT B `:.` It has more RESISTIVITY `(520xx10^(-8) Omega m)` (ii) Element A `:.` It has less resistivity and hence less heating effect. Dissipation of energy during TRANSMISSION of POWER. |
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| 1652. |
Name the three common defects of vision. What are the causes ? Nan1e the type of lens used to correct each of them. |
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Answer» Solution :(i) Myopia: Cause : Elongation of eyeball TYPE of lens used for correction :Concave ]ens of suitable power (ii) Hypcrmetropia : Cause: Shrinking of eye ball Type of lens used for correction : CONVEX lens of suitable power (iii)PRESBYOPIA: Cause: weakening of ciliary muscles TYPES of lens used for correction : Bifocal lens |
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| 1653. |
Mention two cases in which there is no Doppler effect in sound? |
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Answer» SOLUTION :(i) When SOURCE (S) and listener(L) both are at rest. (ii) When S and L MOVE in such a way that distance between them remains constant. (iii) When source Sand L are moving in MUTUALLY perpendicular directions. (iv) If the source is SITUATED at the center of the circle along which the listener is moving. |
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| 1655. |
The loss of one more chromosome in a ploidy is called________. |
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Answer» TETRAPLOIDY |
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| 1656. |
Explain how surface tension can be measured experimentally. |
Answer» Solution :To find surface tension of a liquid in laboratory TORSIONAL BALANCE is used. It is as shown in figure. It consists of a movable metallic rod fixed on a stretched wire. The position or rod can be adjusted. A glass PLATE is attached at one end of the rod and weight's pan is connected at the other end of the rod.  PROCEDURE: A cleaned glass plate is taken. Its length 'l' and thickness 't' is measured . Since thickness t is very small when compared with length 'l', thickness 't' is ignored. Glass plate is fixed to metallic rod. Necessary weights are PLACED in the pan and glass plate is made horizontal to the table. Weights in pan `W_0` is measured. Pure liquid whose surface tension is to be determined is taken in a glass beaker. the liquid is poured until it just touches the glass plate. Now plate is pulled down with some force due to surface tension of liquid. Weights in the pan are gradually increased until the glass plate is just escaped from forces of surface tension. Weights `W_1` are noted. the experiment is repeated for three to four times and average weight `W_1` is noted Surface tension T=`("Force")/("length")` `=((W_1-W_0)=W)/(l e ng th of glass plate i n) ` contact with liquid (2l) `therefore` Surface tension T=`W/(2l)` is measured. |
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| 1657. |
A driver takes 0.20 s to apply the brakes after he sees a need for it. This is called the reaction time of the driver. If he ils driving a car at a speed of 54 km/h and the brakes cause a deceleration of 6.0 m/s^2, find the distance travelled by the car after he sees the need to put the brakes on. |
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Answer» SOLUTION :(DISTANCE COVERED during 0.20 s) + (distance covered until REST) `=(15xx0.25)+[18.75]=21.75m` |
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| 1658. |
List three differentiating features between the processes of galvanisation and alloying. |
Answer» SOLUTION :
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| 1659. |
Two lamps rated 100 W, 220 V and 10 W, 220 V are connected in parallel to 220 V supply. Calculate the total current through the circuit. |
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Answer» Solution :Current passing through 1ST BULB of 100 W, 220 V rating `I_(1)=(P_(1))/(V_(1))=100/220=5/11=A` and current passing through 2ND bulb of 10 W, 220 V rating, `I_(2)=(P_(2))/(V_(2))=(P_(2))/(V_(2))=10/220=1/22=A` Since two bulbs are connected in parallel, total current through the circuit `I=I_(1)+I_(2)=5/11+1/22=11/22 A=1/2 A=0.5 A` |
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| 1660. |
Is the concept of latent heat applicable during transformation of gaseous phase to liquid phase and from liquid phase to solid phase? |
| Answer» Solution :Yes. The latent HEAT of fusion is APPLICABLE to the change from LIQUID to solid or VICE versa. ALSO the latent heat of vapourization is applicable to the change from gas to liquid or vice versa. | |
| 1661. |
State the difference in colours of the sun observed during sunrise/sunset and noon. Give explanation for each? |
| Answer» SOLUTION :The sun rays have to travel through a larger ATMOSPHERIC distance. Asmost of the BLUE light and shorter wavelengths are removed by scattering. Only red colour, which is least scattered is received by our eyes and appears to COME from sun. Hence the APPEARANCE of sun at sunset or sunrise or full noon near the horizon may look reddish. | |
| 1662. |
Dimension of ________can be measured using gravitation law . |
| Answer» SOLUTION :HEAVENLY BODIES | |
| 1663. |
As per the Joule's equation of electrical heating, The heat produced in a register 1.H= ______ Joule. 2. Derive above formula using Ohm's law |
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Answer» Solution :1.H = `I^2Rt` JOULE 2. DERIVATION of the formula : If 'I' is the current flowing continuously through the circuit, the heat produced in the resistor in time't' will be: H= p x t `:.` H = V x I x t(`because` P = V x I) `THEREFORE` H = I x R x I x t (By Ohm's law , V=IR) This equation is CALLED as Joule's law of heating. |
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| 1664. |
List four gases generated in a biogas plant. |
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Answer» Solution :(i) HYDROGEN (ii) Hydrogen sulphide (iii) METHANE (IV) CARBON DIOXIDE |
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| 1665. |
In which arrangement, series on parallel, are various electrical devices connected in the domestic lighting circuit? |
| Answer» SOLUTION :IN PARALLEL | |
| 1666. |
If the image formed is always virtual, the mirror can be : |
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Answer» CONCAVE or convex |
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| 1667. |
Complete the following sentences: (i) The S.I unit of moment of force is……… (ii) In equilibrium, algebraic sum of moments of all forces about all the point of rotation is ……… (iii) In a beam balance, when the beam is balanced in a horizontal position, it is in........... equilibrium. (iv) the moon revolving around the earth is in....... equilibrium. |
| Answer» SOLUTION :(i) N m (ii) ZERO (III) static (IV) dynamic | |
| 1668. |
What are homologous structures ? Give an example. Is it necessary that homologous structures always have a common ancestor. Justify your answer. |
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Answer» Solution :Homologous structures in vertebrates are wings in birds and forelimbs of lizard. They are so named as they have same structural DESIGN but different function. Presence of such organs indicate that these ORGANISMS would have had common ancestor. Various organisms EVOLVED from that ancestor as they had different habits and HENCE, these structures evolved to help them perform different functions. For example : Forelimbs of lizard, frog, bird and man have same structure but help lizard in creeping, frog in juinping, bird in flying and man in PICKING things. |
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| 1669. |
In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution :(A) exchange of atoms takes place.(B) exchange of ions takes place.(C) a precipitate is produced.(D) an insoluble salt is produced.The correct option is : |
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Answer» (B) and (D) |
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| 1670. |
A gas is filled in a container at pressure P_(0). If the mass of molecules is halved and their rms speed is doubled, then the resultant pressure would be |
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Answer» `2Po` |
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| 1671. |
A body at a height possesses: |
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Answer» KINETIC ENERGY |
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| 1672. |
Why a spannerwith a long handle is preferredto tighten screws in heavy vehicles ? |
| Answer» Solution :This is because EFFECT to tighten the screws DEPENDS upon the perpendicular distance of the applied force the ACIS of rotation in power arm . Larger the power arm less is the force required to turn the screws. So spanner is provided with a long HANDLE. | |
| 1673. |
In the glass slab experiment, a student measures the angle of incidence (angle i) in air and finds it to be 40^(@). He also measured the corresponding angle of refraction as well as the angle of emergence for this ray of light but also their record. The most likely record of readings for the angle of incidence and angle of emergence wil be : |
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Answer» `ANGLE R = 40^(@)` and `angle E = 50^(@)` |
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| 1674. |
(i) Two convex lenses A and B have powers P_(1) and P_(2), respectively and P_(2) is greater than P_(1). Draw a ray diagram for each lens to show which one will be more converging. Give reason for your answer. (ii) A 2.0 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm. The distance of the object from the lens is 15 cm. Find the nature, position and size of the image. Also find its magnification. |
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Answer» <P> SOLUTION :(i) `P_(2)gtP_(1):.F_(2)lgF_(1)` B is more converging because rays are refracted more. (ii) `1/u=(-1)/15+1/10=1/30` or `v=+30cm` The IMAGE formed is real and inverted and on the other side of OPTICAL centre `m=(h.)/h=v/uimpliesm=-2` inverted and 4cm tall. |
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| 1675. |
What is visible spectrum ? |
| Answer» SOLUTION :Visible SPECTRUM is band of (seven) COLOUR components of a WHITE light beam produced as a consequence of dispersion phenomenon. | |
| 1676. |
A satellite is revolving around the orbit with a tangential velocity of 6.4 km/s . Determine the radius of the orbit of the satellite. |
| Answer» SOLUTION :`9.7705xx10^(6)MOR 9770 "KM"` | |
| 1677. |
A student wants to project the image of a candle flame on a screen 48 cm in front of a mirror by keeping the flame at a distance of 12 cm from its pole. (i) Suggest the type of mirror he should use. (ii) Find the linear magnification of the image produced. (iii) How far is the image from its object? (iv) Draw ray diagram to show the image formation in this case. |
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Answer» Solution :(i) He should use a concave mirror, as it forms a real image on the same side of the mirror. (ii) Object distace u=12cm Image distance v=-48 CM Magnification `m=-v//u=-(-48)//(-12)=-4` The minus sign in magnification shows that the image formed is ral and INVERTED. (iii) The image is formed at a distance of 36 cm from the object.  In this case the image is formed beyond the CENTRE of curvature. This image is real, inverted and ENLARGED. |
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| 1678. |
Which is the process used to harness nuclear energy these days? Explain it briefly. |
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Answer» Solution :Nuclear fission harnesses nuclear energy these days. The fission of an atom of uranium, for example. produces million times the energy produced by the combustion of an atom of carbon from coal. In a nuclear fission, the difference n mass, `Delta`m, between the original nucleus and the product nuclei, gets converted INTOENERGY E at a rate governed by the equation E= `Delta m c^(3)` , where c is the velocity of light .In a nuclear reactor DESIGNED for electric power generation, such a nuclear .fuel. can be part of a self-sustaining fission chain reaction that releases energy at a controlled rate. the RELEASED energy can be used to PRODUCE steam and further generate electricity. |
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| 1679. |
Gravitational waves: Waves are created on the surface of water when we drop a stone into it. Similarly you must have seen the waves generated on a strintg when both its ends are held in hand and it is shaken. Light is also a type of wave called the electromagnetic wave. Gamma rays, X-rays, ultraviolet rays, infrared rays, microwave and radio waves are all different types of electromagnetic waves. Astronomical objects emit these waves and we receive them using our instruments.All our knowledge about the universe has been obtained through these waves. Gravitational waves are a very different type of waves. They have been called the waves on the fabric of space-time. Insteine predicted their existence in 1916. These waves are very weak and it is very difficult to detect them. Scientists have constructed extremely sensitive instruments to detect the gravitational waves emitted by astronomical sources. Among these, LIGO (Laser Interferometrc Gravitational Wave Observatory) is the prominent one. Exactly after hundred years of their prediction, scientists detected these waves coming from an astronomical source. Indian scientist have contributed significantly in this discovery. This discovery has opened a new path to obtain information about the Universe. Is it easy to detect Gravitational waves? |
| Answer» SOLUTION :No, these WAVES are very WEAK and it is very DIFFICULT to DETECT them. | |
| 1680. |
The halogen whichis liquidat roomtemperatureis _____. |
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Answer» Fiuorine |
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| 1681. |
Gravitational waves: Waves are created on the surface of water when we drop a stone into it. Similarly you must have seen the waves generated on a string when both its ends are held in hand and it is shaken. Light is also a type of wave called the electromagnetic wave. Gamma rays, X-rays, ultraviolet rays, infrared rays, microwave and radio waves are all different types of electromagnetic waves. Astronomical objects emit these waves and we receive them using our instruments.All our knowledge about the universe has been obtained through these waves. Gravitational waves are a very different type of waves. They have been called the waves on the fabric of space-time. Insteine predicted their existence in 1916. These waves are very weak and it is very difficult to detect them. Scientists have constructed extremely sensitive instruments to detect the gravitational waves emitted by astronomical sources. Among these, LIGO (Laser Interferometrc Gravitational Wave Observatory) is the prominent one. Exactly after hundred years of their prediction, scientists detected these waves coming from an astronomical source. Indian scientist have contributed significantly inthis discovery. This discovery has opened a new path to obtain information about the Universe. What is the device, used to detect GRavitational waves? |
| Answer» SOLUTION :LIGO(LASER Interferometric Gravitational waves OBSERVATORY) is used to detect Gravitational waves. | |
| 1682. |
What is Atavism? |
| Answer» Solution :The reappearance of ancestral CHARACTERS in some individuals is CALLED ATAVISM. E.g. PRESENCE of rudimentary TAIL in new born babies. | |
| 1683. |
Gravitational waves: Waves are created on the surface of water when we drop a stone into it. Similarly you must have seen the waves generated on a string when both its ends are held in hand and it is shaken. Light is also a type of wave called the electromagnetic wave. Gamma rays, X-rays, ultraviolet rays, infrared rays, microwave and radio waves are all different types of electromagnetic waves. Astronomical objects emit these waves and we receive them using our instruments.All our knowledge about the universe has been obtained through these waves. Gravitational waves are a very different type of waves. They have been called the waves on the fabric of space-time. Insteine predicted their existence in 1916. These waves are very weak and it is very difficult to detect them. Scientists have constructed extremely sensitive instruments to detect the gravitational waves emitted by astronomical sources. Among these, LIGO (Laser Interferometrc Gravitational Wave Observatory) is the prominent one. Exactly after hundred years of their prediction, scientists detected these waves coming from an astronomical source. Indian scientist have contributed significantly in this discovery. This discovery has opened a new path to obtain information about the Universe. What are the different types of electro magnetic waves? |
| Answer» Solution :Gamma RAYS, X-rays, Ultraviolet rays, infrared rays, MICROWAVE and RADIO waves. | |
| 1684. |
What is the shape of V-I graph for a metallic wire? Why? |
| Answer» SOLUTION :A STRAIGHT inclined line passing through the origin because for a METALLIC wire `V prop I` | |
| 1685. |
Gravitational waves: Waves are created on the surface of water when we drop a stone into it. Similarly you must have seen the waves generated on a strintg when both its ends are held in hand and it is shaken. Light is also a type of wave called the electromagnetic wave. Gamma rays, X-rays, ultraviolet rays, infrared rays, microwave and radio waves are all different types of electromagnetic waves. Astronomical objects emit these waves and we receive them using our instruments.All our knowledge about the universe has been obtained through these waves. Gravitational waves are a very different type of waves. They have been called the waves on the fabric of space-time. Insteine predicted their existence in 1916. These waves are very weak and it is very difficult to detect them. Scientists have constructed extremely sensitive instruments to detect the gravitational waves emitted by astronomical sources. Among these, LIGO (Laser Interferometrc Gravitational Wave Observatory) is the prominent one. Exactly after hundred years of their prediction, scientists detected these waves coming from an astronomical source. Indian scientist have contributed significantly in this discovery. This discovery has opened a new path to obtain information about the Universe. What are the waves on the fabric of space time called? |
| Answer» SOLUTION :They are CALLED GRAVITATIONAL WAVES. | |
| 1686. |
What is the essential difference between an electron and a beta ray ? |
| Answer» SOLUTION :The ELECTRONS of nuclear origin is CALLED a beta -particle . There is OTHERWISE no difference between an ELECTRON and a beta-particle. | |
| 1687. |
The density of water is minimum at ............ . |
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Answer» `0^@C` |
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| 1688. |
Nowdays school going children suffer from mental stress. |
| Answer» Solution :These days children stay in nuclear families Due to need for earning and also due to her career choices. Mother of the house in also AWAY for long period of time. The grandparents or other elders are not in the home. This makes the children alone in the house. At SCHOOL and during studies, there is fierce competition,The modern technology like internet or mobile phones are luring the children away from their regular exercises or outdoor games. The wrong kind of peer pressure introduces addictive substances at the young age. There is insecurity in the outside world for the young children. These FACTS create emotional burden on the young minds and thus they suffer from mental stress. | |
| 1689. |
Define torque and mention its unit. |
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Answer» SOLUTION :(i) The rotating or turning EFFECT of a force about a fixed POINT or fixed axis is called MOMENT of the force about that point or torque `(tau)`. `tau=Fxxd` (iii) Torque is a vector quantity. (iv) Its SI unit is N m. |
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| 1690. |
Time taken by a body in (20 +-0.2) second in undergoing a displacement of (200 +-5)m. Calculate the percentage error in calculation of velcoity. |
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Answer» Solution :Percentage error in measurement of displacement = `(5)/(200)xx100` Percentage error in measurement of time = `(0.2)/(20)xx100` `THEREFORE` MAXIMUM PERMISSIBLE error = `2.5 + 1 = 3.5%` |
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| 1691. |
Mr. Ramu is working as an X-ray technician in a hospital . But, he does not wear the lead aprons. What suggestion will you give to Mr. Ramu ? |
| Answer» Solution :X-rays have destructive effect on living tissue. When the human body is exposed to X-rays, it causes redness of the skin, SORES and serious INJURIES to the tissues and glands. They destory the white corpuscles of the blood. If you doesn.t wear the lead aprons these kinds of DISEASES FORMED in your body. In my suggestion you must wear the lead aprons. | |
| 1692. |
Centrifugal force is: |
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Answer» a) a real force |
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| 1693. |
Radiation leakage occurred after a blast in atomic energy plant at ............. in Russia. |
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Answer» |
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| 1694. |
A 5.0 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 30 cm. By calculation, determine (i) the position (ii) the size of the image formed. |
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Answer» Solution :Here, `h_(1)= 5.0cm, f=20cm,u = -30 cm,v=?, h_(2)=?` From `(1)/(v) - 1/u =(1)/(f), (1)/(v) = (1)/(f) + 1/u = 1/20 - 1/30 =(3-2)/(60) =1/60` or `v=60cm`. `:.` image is formed on the other side of the LENS at 60 cm from the lens. From `(h_(2))/(h_(1)) =v/u, h_(2) =v/u XX h_(1)=60/-30 xx 5.0 = -10cm` Negative sign shows that image is inverted and real. Its SIZE is 10cm. |
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| 1695. |
By whichinstrumentcan the presence of magneticfieldbe determined ? |
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Answer» VOLTMETER |
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| 1696. |
Name the phenomenon by which carbohydrates are oxidized to release ethyl alcohol. |
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Answer» KREB's cycle |
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| 1697. |
Name three different glands associated with the digestive system in humans. Also name their secreations. |
| Answer» Solution :These glands and their SECREATION are -(i) SALIVARY gland , its SECRETION is salilva, (II) Liver , it secretion is called bile juice (III) pancreas: Its secretion is pancreatic juice. | |
| 1698. |
Distinguish between the physical properties of metals and nonmetals with respect to the point : Hardness |
| Answer» SOLUTION :Hardness : Metals are usually hard, but not brittle, EXCEPTIONS : sodium, potassium, lead, ZINC. NONMETALS are brittle in the solid staet, exception : diamond. | |
| 1699. |
Explain how dew and fog are formed. OR Write a short note on formation of dew and fog. |
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Answer» Solution :At a particular temperature , a given volume of air can contain a certain maximum amount of water vapour.Normally , the temperature of air duringthe day is such that air is not saturated with water vapour present in it. As the temperaturefalls, the capacity of air to HOLD water vapour becomes less.During a cold night,the temperature of air may fall to the DEW point, or EVEN belowthe dew point. If the temperature falls below the dew point, the excess of water vapour in air condenses on the surfaces of cold bodies anddew is formed. If thewater vapour condenses on the fine dust particles present in the atmosphere, mist of FOG is formed. |
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| 1700. |
A person with a myopia eye cannot see objects beyond a distance of 1.5 m. What would be the power of the corrective lens used to restore proper vision ? |
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Answer» <P> Solution :The corrective lens should make the OBJECTS at infinity appear at the far point.`:.`For object at infinity, object distance `= u = -oo`. For the myopic EYE, far-point distance, v = -1.5 m. By lens formula `(1)/(f) = (1)/(u) - (1)/(v) = (1)/(-1.5) - (1)/(-oo) = (1)/(-1.5) + 0 = (1)/(-1.5)` f = -1.5 m. POWER , `P = (1)/("f(in m)") = (1)/(1.50) = -0.67 D` Negative sign shows that the corrective lens is a concave. |
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