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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.
| 7301. |
Three resistors 2 Ω, 3Ω and 4Ω are connected so that the equivalent resistance is 9Ω. The resistors are connected |
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Answer» all in SERIES |
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| 7302. |
The unit of momentum in SI system is ___________. |
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Answer» `MS^(-1)` |
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| 7303. |
""_(92)U^(235) experiences one alpha - decay and onebeta- decay. Find number of neutrons in the final daughter nucleus that is formed. |
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Answer» SOLUTION :Let X and Y be the resulting nucleus after the emission of the ALPHA and beta particles respectively `""_(92)U^(235) overset(alpha "decay") to ""_(90)X^(231)+ ""_(2)He^(4)` `""_(90)X^(231) overset(beta "decay") to ""_(91)Y^(231) + ""_(-1)e^(0)` Number of neutrons = Mass number - Atomic number = 231 -91 = 140 |
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| 7304. |
Amar is using spectacles with power - 2.5 D. What will be the focal length (in cm) of the lens used in spectacles? What is the type of the lens and what must be the defect of vision Amar is suffering from? |
| Answer» SOLUTION :f=-40 cm, LENS is concave lens, MYOPIA (NEARSIGHTEDNESS) | |
| 7305. |
The transfer of heat energy continues until the bodies attain the same _______________. |
| Answer» SOLUTION :THERMAL ENERGY | |
| 7306. |
________doesnotoccurduring the productionof rainbow . |
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Answer» REFRACTION |
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| 7307. |
Define water of crystallisation. Give the chemical formula for two compounds as examples. How can it be proved that the water of crystallisation makes a difference in the state and colour of the compounds? |
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Answer» Solution :• Water of crystallisation is the fixed NUMBER of water molecules present in one formula unit of a salt. • `CuSO_(4).5H_(2)O` `FeSO_(4).7H_(2)O` • Take one gram of powder COPPER sulphate crystals `(CuSO_(4).5 H_(2)O)` which are BLUE in colour in a dry China dish. It losses water molecules and a white powder `(CuSO_(4))` is obtained. Cool and ADD a few drops of water to the white powder. Blue colour is restored because of the formation of copper sulphate hydrated `(CuSO_(4).5H_(2)O)`. We CONCLUDE that water of crystallisation makes a difference in the state and colour of the compound. |
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| 7308. |
Why do you wait for periods of music, P.T., drawing in the classroom ? |
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Answer» Solution :i.Learning and listening to the music, SINGING, exercising, playing sports and drawing or sketching are activities which keep us happy and drive away the stress. ii. In schools, children tend to GET stressed by studying various subjects. The above MENTIONED periods bring a LITTLE RELIEF and help them de-stress. |
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| 7309. |
List any three differences between convex lens and concave lens. |
| Answer» SOLUTION :`{:("Convex lens","Concave lens"),("It is CURVED outward - thicker at the center and thinner at the edges.","It is curved inwards - thinner at the center and thicker at the edges."),("It converges incident lights rays to a point.","It diverges incident LIGHT rays."),("Focal length is positive.","Focal length is negative."),("Forms REAL and inverted image.","Forms virtual, erect and diminished image."),("Objects appear closer and larger.","Objects appear smaller and farther."),("Used to CORRECT hypermetropia.","Used to correct myopia."):}` | |
| 7310. |
Equal torques are applied on a cylinder and a hollow sphere. Both have same mass and radius. The cylinder rotates about its axis and the sphere rotates about one of its diameters. Which will acquire greater speed ? Explain. |
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Answer» SOLUTION :`tau = IALPHA, ALPHA = tau/I` `alpha` in cylinder, `alpha_(C) = tau/I_(C)` `alpha` in cylinder `alpha_(S) = tau/I_(S)` `alpha_(C)/alpha_(S) = I_(S)/I_(C) = (2/5 MR^(2))/(MR^(2)) -2/5` |
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| 7311. |
The three R's that will help us to conserve natural resources for long term use are |
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Answer» recycle, regenerate, reuse Recycle This means COLLECTION of materials like PLASTIC, paper, glass etc,. To make required things instead of synthesising or extracting fresh plastic, paper, glass etc. Reuse Insteady of THROWING articles, (e.g., used envelopes) use it again. This is better than recycling because recycling process uses some energy. |
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| 7312. |
Name two special characteristics of heating coil. |
| Answer» SOLUTION :HIGH RESISTIVITY and high MELTING POINT. | |
| 7313. |
State Rayleigh's law of scattering. |
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Answer» SOLUTION :Rayleigh.s scattering law states that, "The amount of scattering of light is inversely proportional to the fourth power of its wavelength". .S. `OO (1)/(LAMBDA^(4))` |
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| 7314. |
What is a variable resistance ? Give one example of it. |
| Answer» SOLUTION :A component used to regulate current without CHANGING the voltage source in an electric circuit is called VARIABLE RESISTANCE. e.g. rheostat. | |
| 7315. |
A body of mass 50 kg is at rest. The work doen to accelerate it by 20m/s in 10 s is |
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Answer» `10^(3)J` `W=FxxS=10^(4)J` |
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| 7316. |
What are the two factors on which the lateral displacement of an emergent ray from a glass slab depends ? |
| Answer» Solution :LATERAL displacement DEPENDS on (i) thickness of GLASS slab and (ii) ANGLE of incidence. | |
| 7317. |
Three students measured the focal length of a convex lens using parallel rays from a distant object. All of the measured the distance between the lens and the inverted image on the screen. (i) Student A saw a sharp image on the screen and labelled the distance as f_(1) (ii) Student B saw a slightly larger blurred image on the screen and labelled the distance as f_(2) (iii) Student C saw slightly smaller blurred image on the screen and labelled the distance as f_(3) The relation between the three measurements would most likely be : |
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Answer» `f_(1) = f_(2) = f_(3)` |
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| 7318. |
A body is moving along z-axis of a coordinate system under the effect of a constant force F=(2hati+3hatj+hatk)N. Find the work done by theforce in moving the body a distance of 2m along z-axis. |
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Answer» SOLUTION :`VECF=(2hati+2hatj+hatk)N,vecS=2hatk` `W=vecF.vecS=2J` |
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| 7319. |
Electrical reslstivities of some substances, In ohm- meter, at 20^(@) C are given as follows : Name the material that you would advise to beused in the heater elements of electric heating , device and why ? |
| Answer» SOLUTION :Nichrome, Very high resistivity / as it is an alloy, it does not oxidize READILY at high TEMPERATURE. | |
| 7320. |
An object is kept at 60 cm in front of convex lens of focal length 15 cm. Find the image distance and the nature of the image . Also find the magnification produced by the lens . |
| Answer» SOLUTION :`v=20` cm . The image is real, INVERTED and SMALLER than the OBJECT . `M=- 1/3` | |
| 7321. |
Three resistors of values 2Omega,4Omegaand6Omega are connected in parallel. Find the equivalent resistance of combination. |
| Answer» SOLUTION :`1.09Omega` | |
| 7322. |
A TV of rating 80 W operates2 hours/day. Find the number of units consumed by the TV in a year. |
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Answer» |
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| 7323. |
Latent heatis evovled duringthetransformationof liquidsintosolids .'Howwill youexplainthisstatement ? |
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Answer» HEAT RELEASED andtemperaturedecreases |
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| 7324. |
Nichrome wire of length l and radius r has resistance of 10 Omega . How would the resistance of the wire change when : (i) Only length of the wire is doubled ? (ii) Only diameter of the wire is doubled ? Justify your answer . |
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Answer» Solution :(i) `R prop L` So resistance BECOMES TWO times i.e R `=20 Omega` (II) `R prop (1)/(A) prop (1)/(d^(2))` So when diameter is doubled resistance becomes one fourth of the original i.e., R = 2.5 `Omega` |
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| 7326. |
A resistances wire is stretched so as to double its length. Its new resistivity will have a magnitude |
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Answer» 2 times its ORIGINAL value |
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| 7327. |
A coil of insulated copper wire is connected to a galvanometer. What would happen if a strong bar magnet is: (a) pushed into the coil? (b) withdrawn from inside the coil ? (c) held stationary inside the coil ? Give justification for each observations. |
| Answer» SOLUTION :SEE NCERT Textbook Exercises QUESTION Number 13. | |
| 7328. |
Principle of buoyancy ………….. |
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Answer» Archimedesp |
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| 7329. |
What is tyndall effect? |
| Answer» Solution :The scattering of LIGHT by COLLOIDAL solution is called tyndall EFFECT. | |
| 7330. |
Answer the following questions. a. What is overloading? b. Effect of overloading. c. Preventive measures. |
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Answer» Solution :1.The current owing in domestic wiring at a particular time depends on the POWER ratings of the appliances being used. If too many electrical appliances of high power rating are SWITCHED on at the same time, they draw an EXTREMELY large current from the circuit. This is known as overloading. b. Effects: Due to the large amount of flowing current through them, the copper wires of household wiring gets HEATED to a very high temperature and may lead to fire. C. Preventive measures : The damage due to overloading can be prevented by using good quality electrical materials, such as Fuse and MCB |
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| 7331. |
Let the resistance of an electrical components remains constant while the potential difference across the two ends of the component decreases to half to its former value. What change will occur in the current through it? |
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Answer» Solution :It is given that resistance R of the ELECTRICAL component remains constant but the potential difference across the two ENDS of the component decreaseto HALF of its value i.e., `V.=V/2` Hence, as PER Ohm law new CURRENT `l.=V./R=(V//2)/R=V/(2R)=l/2` SO, the new current decreases to half of its original value. |
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| 7332. |
What happens to the resistance, as the conductor is made thicker ? |
| Answer» Solution :If the CONDUCTOR in made THICKER area of cross section of conduction increases that will decreases the RESISTANCE. | |
| 7333. |
Are able to listen to the sound ? If not why? |
| Answer» Solution :We are unable to hear the SOUND. If we lift ONE of the pipes then the PIPE carrying incident sound, the pipe carrying REFLECTED sound will not be in the same plane. Hence we cannot hear the sound. | |
| 7334. |
Why do we get colours when white light passes through a prism ? |
| Answer» Solution :LIGHT of DIFFERENT COLOURS bend through different angles while passing through a prism. | |
| 7335. |
Then diagram given below shows a ski jump.A skier weighing 60 kgf stands at A at top of ski jump.He moves from A and takes off for his jump at B. (a)Calculate the change in the gravitational potential energy of the skier between A and B. (b)If 75 % of the energy in part (a)becomes kinetic energy at B,calculate the speed at which the skier arrives at B. (Take g=10 m s^(-2)) |
| Answer» Solution :(a)`3.6xx10^(4)`J (B) 30 m `s^(-1)` | |
| 7336. |
A woman draws water from a well using a fixed pulley. The mass of bucket and water together is 6 kg. the force applied by the woman is 70 N. calculate the mechanical advantage. (Take g=10ms^(-2)) |
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Answer» |
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| 7337. |
Sketch the concept diagram to show steps in the process of tissue culture . |
Answer» SOLUTION :
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| 7338. |
Due to ....... .... .. , every information is available at our fingertips. |
| Answer» SOLUTION :INTERNET | |
| 7339. |
Linearmomentum is p=____________ |
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Answer» `"mass" XX" velocity"` |
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| 7340. |
A light ray is incident at an angle of 60^(@) at the interface of Medium X and medium Y air - water interface. If the angle of refraction is 30^(@).(i) Draw a diagram to represent the same.(ii) Find the refractive index of the Y with respect to medium X.(iii) If medium Y has a refractive index equal to 4/3, will the angle of refraction increase or decrease ? |
Answer» Solution :(i) (ii) `mu_(yx)=(sin i)/(sin r)=(sin 60^(@))/(sin 30^(@))=((sqrt(3))/(2))/((1)/(2))=(sqrt(3))/(2)xx(2)/(1)=sqrt(3)=1.73` (iii) If medium Y is replaced with a medium of refractive index 4/3 (= 1.33), then medium Y is optically rarer than the medium with refractive index = 1.73, the ANGLE of REFRACTION will be more than `30^(@)`. |
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| 7341. |
Locomotion is considered as an important characteristics of the animals . However , animalsbelonging to Porifera are said to be sedentary . Every other phylum has typical locomotory organs E.g. Nereis crawls with the help of parapodia , whereas earthworm buries in soil by setae . Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages . Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion . Birds flying with their spread out wings and fish swimming such body offers least resistance during locomotion . Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging like snake are limbless. Other animals belonging to the class of snakes also have very weak limbs which make them creep on the ground. Which class of animals show weak legs ? |
| Answer» SOLUTION :Class Retilia belonging to subphylum VERTEBRATA SHOW weak LEGS. | |
| 7342. |
Locomotion is considered as an important characteristics of the animals . However , animalsbelonging to Porifera are said to be sedentary . Every other phylum has typical locomotory organs E.g. Nereis crawls with the help of parapodia , whereas earthworm buries in soil by setae . Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages . Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion . Birds flying with their spread out wings and fish swimming such body offers least resistance during locomotion . Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging like snake are limbless. Other animals belonging to the class of snakes also have very weak limbs which make them creep on the ground. In which class of animals the forelimbs are modified ? |
| Answer» SOLUTION :CLASS AVES belonging to subphylum vertebrata have wings which are MODIFIED forelimbs. | |
| 7343. |
Define particle velocity. |
| Answer» SOLUTION :The velocity with which the particles of the medium vibrate in order to TRANSFER the ENERGY in the FORM of a wave is called particle velocity. | |
| 7344. |
Oil slick : Alcanovorax : : Rubber from garbage : ….. |
| Answer» SOLUTION :Actinmycetes | |
| 7345. |
Whether the places of disasters are known to you ? Discuss the effects of these effects of these disasters on public life. How people could have been saved from these disasters ? Discuss with your friends in the classroom. |
| Answer» Solution :Students should DISCUSS the disasters GIVEN in the PICTURES by themselves after COLLECTING the information. | |
| 7346. |
How is the type of current received in a domestic circuit different from one thatruns a clock ? |
| Answer» Solution :The current received in a domestic circuit is an alternatingcurrent [AC], while that which runs a CLOCK is a DIRECT current [DC] . | |
| 7347. |
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 the pole of the mirror.(a) Suggest the type of mirror he should use.(b) Find the linear magnification of the image produced.(c ) How far is the image from the object ? (d) Find the focal length of the mirror.(e ) Draw a ray diagram to show the image formation in this case. |
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Answer» SOLUTION :(a) Concave mirror as only concave mirror can produce real IMAGES. (b) `u=-12 cm "" v=-48 cm` `m=-(v)/(u)` Linear magnification `m=-((-48)/(-12))=-4` The minus indicates that the image is diminished and real and inverted image. (c ) Distance of the candle from the screen `= 48-12=36 cm` (d) `(1)/(v)+(1)/(u)=(1)/(f)` `(1)/((-48))+(1)/((-12))=(1)/(f), f=-(48)/(5)=-9.6 cm` This SHOWS that the OBJECT is placed between the C and F of the concave mirror. (e ) 
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| 7348. |
Explain the construction of simple microscope and derive its magnification power. |
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Answer» Solution :Simple Microscope: Simple microscope is a convex lens of short focal length. It is held near the eye to GET enlarged image of small objects. Let an object (AB) of height .h. is placed at a point within the PRINCIPAL focus (u<F) of the convex lens and the A. observer.s eye is placed just behind the lens. As per this position the convex lens produces an erect, virtual and enlarged image (A.B.). The image formed in the same side of the object and the distance equal to the least distance of distinct vision (D) Magnification power (M): Ratio of the height of the image produced by the microscope `(h_(2))` to the original height of the object(h) is called Magnification `M=(A’B’)/(AB)` Magnification `M =("height of the imagens" )/( "height of the object")=(h_(2))/(h_(1))` Magnification can also be defined as the ratio of the distance of image (v) to the distance of object(u) Magnification `M=("Distance of the image")/("Distance of the object")=(nu)/(u)` Since the image is virtual and erect, the magnification (M) is taken as positive, In simple microscope, When the image is formed at the near point `M=1+(D)/(f)` When the image is formed at infinity `M=(D)/(f)` (ii) Write the uses of simple microscope. (i) By watch repairers and jewellers. (ii) To read small letters clearly. (iii) To observe parts of flower, insects etc. (iv) To observe finger prints in the field of FORENSIC science. 
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| 7349. |
Locomotion is considered as an important characteristics of the animals . However , animalsbelonging to Porifera are said to be sedentary . Every other phylum has typical locomotory organs E.g. Nereis crawls with the help of parapodia , whereas earthworm buries in soil by setae . Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages . Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion . Birds flying with their spread out wings and fish swimming such body offers least resistance during locomotion . Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging like snake are limbless. Other animals belonging to the class of snakes also have very weak limbs which make them creep on the ground. Which phylum has a characteristic or jointed appendages ? |
| Answer» SOLUTION :Phylum ARTHROPODA has a characteristic of JOINTED appendages. | |
| 7350. |
Locomotion is considered as an important characteristics of the animals . However , animalsbelonging to Porifera are said to be sedentary . Every other phylum has typical locomotory organs E.g. Nereis crawls with the help of parapodia , whereas earthworm buries in soil by setae . Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages . Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion . Birds flying with their spread out wings and fish swimming such body offers least resistance during locomotion . Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging like snake are limbless. Other animals belonging to the class of snakes also have very weak limbs which make them creep on the ground. Which the locomotory organ of animals belong to Phylum Mollusca ? |
| Answer» SOLUTION :Animals belonging to Phylum MOLLUSCA have strong MUSCULAR foot which is USED for locomotion. | |