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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.
| 2451. |
The focal length of a converting lens are f_(v) and f_(r) for violet and red lights, respectively. Which of the following is correct? |
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Answer» `f_(1) = f_(2)` |
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| 2452. |
Derive an expression for the variation of acceleration due to gravity below the surface of the Earth. |
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Answer» Solution :VARIATION of accleration due to gravity below the surface of earth : At a depth 'd' inside the ground mass of earth upto the point d from CETRE will exhibit force of attraction on the body. The remaining mass does not exhibit any influence. Mass of spherical body `M prop R^3` `:. M_s`/`M_E=(R_E-d)^3`/`R_E^3` where `M_S` is mass of earth's shell upto a depth 'd' from CENTRE. Gravitational force at depth 'd' is `F(d)=GM_s`m/`(R_E-d)^2=GM_Em(R_E-d)`/`R_E^2` `:.g(d)=(F(d))/(m)=(GM_E)/(R_E^3)(R_E-d)=g(R_E-d)=g(1-(d)/(R_E))` So 'g' VALUE decreases with depth below the ground. |
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| 2453. |
Man-made redioactivity is also known as ______________ |
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Answer» INDUCED radioactivity |
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| 2454. |
Shaliniand his brotherAmeyobserveda water-pump working, Shaliniinquired howan electric motorworks . Amey collected differentpartsof an electricmotore.g.,field - magnets , cabon- brushes ,armature, battery, switch, connecting wire , split- rings , etc, and showedthem to Shalini . Ameythen explainedhow an armature could rotate.Is an electric motorneeded for water - pump to work ? |
| Answer» SOLUTION :Yes. An electricmotoris needed for water - PUMP to WORK . | |
| 2455. |
Name some sources of direct current |
| Answer» SOLUTION :Some SOURCES of direct current are a CELL, a BATTERY and a D.C GENERATOR | |
| 2456. |
Shaliniand his brotherAmeyobserveda water-pump working, Shaliniinquired howan electric motorworks . Amey collected differentpartsof an electricmotore.g.,field - magnets , cabon- brushes ,armature, battery, switch, connecting wire , split- rings , etc, and showedthem to Shalini . Ameythen explainedhow an armature could rotate.Statethe principlehowan electricmotor to works . |
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Answer» SOLUTION :WHENA current -carryingcoil is placedin a MAGNETICFIELD,it experiences a FORCE . THEDIRECTION of thisforceis foundbyusingthe Fleming.s left - handrule . |
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| 2457. |
Suggest the measures for conservation of biodiversity . |
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Answer» Solution :i. CONSERVATION of all plants animals. ii. Protection of rare species of organisms. iii. Projects for conservation of special species. iv. ESTABLISHMENT of national parks and sanctuaries. v. Declaration of some REGIONS as bioreserves. vi. MAINTENANCE of records of traditional knowledge. vii. Obey the rules that fall under Biodiversity Act. |
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| 2458. |
A spherical mirror and a thin spherical lens have each a focal length of - 15 cm. The mirror and the lens are likely to be. |
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Answer» Both CONCAVE |
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| 2459. |
The atomic number of three elements A, B and C are given below : {:("Element",A,B,C),("Atomic number",5,7,10):} Answer the following: (a) Write the group number of the three elements in the Modern Periodic Table. (b) Mention the period of these elements in the Modern Periodic Table. (c) Out of these three elements which one has the smallest atomic radius and why ? |
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Answer» SOLUTION :(a) `{:("Element:",A,B,C),("Atomic number:",13,15,18):}` (b) All the three ELEMENTS BELONGS to the second period. (c) 'C' is SMALLEST, as the atomic size decreases from left to right in a period. |
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| 2460. |
Shaliniand his brotherAmeyobserveda water-pump working, Shaliniinquired howan electric motorworks . Amey collected differentpartsof an electricmotore.g.,field - magnets , cabon- brushes ,armature, battery, switch, connecting wire , split- rings , etc, and showedthem to Shalini . Ameythen explainedhow an armature could rotate.What values doyou learn from Amey.s activities ? |
| Answer» SOLUTION :APTITUDE for PRACTICAL DEMONSTRATION andenthusisam to LEARN. | |
| 2462. |
What is the chemical formula of GYPSUM ? Write chemical equation for its preparation. |
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Answer» Solution :Chemical FORMULA of Gypsum is `CaSO_(4).2H_(2)O` Equation for its PREPARATION `underset("(Plaster of PARIS)")(CaSO_(4).1/2H_(2)O) +1 1/2 H_(2)O to CaSO_(4).2H_(2)O` |
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| 2463. |
State the use of earth wire in domestic elecbic circuit. |
| Answer» Solution : To ensure that any LEAKAGE of current to the metallic body of the APPLIANCE does not GIVE SHOCK to the USER. | |
| 2464. |
What is virtual image? |
| Answer» Solution :If the rays of LIGHT DONOT actually meet after reflection or REFRACTION, but appear to meet when produced backwards, then that POINT CONSTITUENTS virtual image. | |
| 2465. |
What is the nature of eye lens ? Is its focal length fixed ? |
| Answer» SOLUTION :Eye lens is a DOUBLE convex lens. Its focal length is not fixed, but adjustable, because its CURVATURE can be modified to some extent by the ciliary muscles HOLDING the lens. | |
| 2466. |
Observe the diagram given and aswer the question asked. c. What changes are seen in 'B' while coming out of a cinema hall and entering in a dark place from brightly lit area? |
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Answer» Solution :1. While coming out from a cinema HALL the pupil constricts to reduce the amount of light ENTERING. 2. While entering into a dark room, the pupil DIALECTS to INCREASE the amount of light entering. 
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| 2467. |
Frog , Tortoise , Toad , Salamander |
| Answer» SOLUTION :TORTOISE . (Tortoise is a REPTILE , the REMAINING are AMPHIBIANS . ) | |
| 2468. |
An object placed on a metre scale at 8 cm mark was focussed on a white screen placed at 92 cm mark, using a converging lens placed on the scale at 50 cm mark. (i) Find the focal length of the converging lens. (ii) Find the position of the image formed if the object is shifted towards the lens at a position of 29 cm. (iii) State the nature of the image formed if the object is further shifted towards the lens. |
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Answer» Solution :(i) Here position of object on METRE SCALE = 8 cm, position of converging (convex) LENS = 50 cm and position of screen = 92 cm `therefore` u = (50 - 8) = 42 cm and v = (92 - 50) = 42 cm As per sign CONVENTION u = - 42 cm and v = + 42 cm `therefore""(1)/(f) = (1)/(v) - (1)/(u) = (1)/((+42)) - (1)/((-42)) = (1)/(42) + (1)/(42) = (1)/(21) rArr f = 21` cm (ii) If object is shifted to a position 29 cm, then u. = (50 - 29) cm = 21 cm i.e., the object is situated at first focus `F_(1)` of the lens. Hence its real and inverted image is formed at infinity. (iii) If the object is further shifted towards the lens then `|u| lt f` and hence a virtual and erect image of the object will be formed. |
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| 2469. |
Where does alcohol effect immediately after drinking ? |
| Answer» Answer :A | |
| 2470. |
Which of the following is formed by interlinking of different food chains? |
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Answer» Ecosystem |
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| 2471. |
Which of the following is not a unit of distance? (i) Light year (ii) Parsec (iii) Leap year (iv) angstrom |
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Answer» LIGHT YEAR |
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| 2473. |
What are hot spots inside earth's crust ? |
| Answer» SOLUTION :Hot spots are place within the mantle where rocks MELT to GENERATE magma. | |
| 2474. |
The effect take place while falling freely in roller coasteris _________. |
| Answer» SOLUTION :WEIGHTLESSNESS | |
| 2475. |
Distinguish between bipolar neuron an multipolar neuron. |
Answer» SOLUTION :
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| 2476. |
what legislative measures are taken in india to to conserve wildlife? |
| Answer» SOLUTION :in india, several laws and acts have been passed from time to time in ORDER to protect the degrading wildlife.out of all,the wildlife protection act of 1972 has been the most effective. Under this act , possession , TRAPPING , shooting of wild animals alive or DEAD, serving their meat for eating in houses, using them as transport, etc.,are completely under strict control or PROHIBITED. | |
| 2477. |
State the approximate value of the critical angle for (a) glass-air surface (b) water-air surface. |
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Answer» (B) `49^(@)`. |
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| 2478. |
Abbreviation of ICRP _________________ |
| Answer» SOLUTION :INTERNATIONAL COMMISSION on RADIOLOGICAL PROTECTION | |
| 2479. |
A thin layer of water is transparent but a very thick layer of water is |
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Answer» translucent |
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| 2480. |
In question 68 above, the average velocity of the car is |
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Answer» `10MS^(-1)` |
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| 2481. |
Find the gravitational potential energy of 1 kg mass kept at a height of 5 m above the ground Calculate its kinetic energy when it falls and hits the ground. Take 10 ms^(-2) |
| Answer» SOLUTION :50 J ,50 J | |
| 2482. |
Manoj is a twelve year old boy. He obtained a lens from one of his friends. Manoj held the lens towards him and start looking at sun, his brother snatched away the lens from him. The brother firmly told Manoj not to do it again. (a) What could be the nature of the lens ? (b) Why did the brother snatch the lens from Manoj ? (c) What could have happened toManoj if his brother had not snatched away the lens from him ? Explain. (d) What values are shown by Manoj's brother ? |
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Answer» Solution :(a) It is convex lens (which is a CONVERGING lens). (b) The brother snatched away the convex lens from Manoj because looking at the sun through convex lens could damage the eye of Manoj. (c) Convex lens is a converging lens. It could converge (or CONCENTRATE) a lot of sun's rays or sun's ENERGY into Manoj's eyes. This energy could damage the delicate retina of eyes and even make him blind. (d) The values shown by Manoj's brother are (i) AWARENESS (having knowledge) of the properties of convex lens and (II) Concern for the eyes of his brother Manoj. |
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| 2484. |
On the basis of structure of disaster - management authority, form the same for your school. |
Answer» SOLUTION :
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| 2485. |
Name the part of the human eye that helps in changing the focal length of the eye lens. |
| Answer» SOLUTION :CILIARY MUSCLES. | |
| 2486. |
Mrs. Anita Pandey observed that her cooking utensils are becoming black in colour and the flame of her gas stove is yellowish in colour. She complains about it in the gas company and got the gas stove repaired. Answer the following questions based on the above situation: (i) What can be the reason for this sooty flame? (ii) How is this problem harmful for our environment? (iii) What steps should be taken to stop this process? (iv) What values are promoted by Mrs. Pandey? |
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Answer» Solution :(i) The inlets for air in stove GET blocked which leads to yellow FLAME. (ii) This problem is harmful for our environment as incomplete combustion results in the formation of oxides which are MAJOR pollutants of our environment. (iii) For preventing this SITUATION, gas or stove burners should be cleaned time to time. (iv) Prudency, careful observation, decision MAKING. |
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| 2487. |
Splitting up of a heavier nucleus into two smaller nuclei is called nuclear fusion. |
| Answer» Solution :Splitting up of a heavier NUCLEUS into SMALLER NUCLEI is called nuclear fission. | |
| 2488. |
Assertion : Astronomical telescope is used to view heavenly bodies. Reason : Telescope is easily protable. |
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Answer» Both ASSERTION and REASON are true and reason is CORRECT explanation of assertion. |
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| 2489. |
Which precautions will you followto maintainthe reproductive health ? |
| Answer» Solution :(1) The reproductive system is one of the organ systems in the bodyjust like the other systems.(2) Therefore, about reproductive health oneshould have scientific and authentic information . (3) The cleanliness of body is very essential but essential but keeping the mind clean is also important to MAINTAIN good reproductive health. (4) One should be careful about sexual relationships. These THINGS should not beexperimented in young age. (5) Mistakes COMMITTED like this can change the sexual health forever. (6) The cleanliness and HYGIENE during menstruation, the cleanliness of genitals and hygiene during menstruation, the cleanliness of genitals and other private parts are the aspects of personal hygiene. (7) When living in a society, one should always be away from cross - infections of venereal type. | |
| 2490. |
A chemical compound X is used in the soap and glass industry. It is prepared from brine. What happens when it is treated with water containing Ca or Mg salts ? |
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Answer» Solution :It removes PERMANENT HARDNESS of water which is due to the presence of CALCIUM and MAGNESIUM salts. `CaCl_(2) + Na_(2)CO_(3) rarr CaCO_(3) + 2NaCl` |
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| 2491. |
How does kinetic throry justify Avogadro's hypothesis and show that Avogadro Number in different gases is same? |
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Answer» Solution :Avogadro.s law or Avogadro.s hypothesis: It STATES that "equal VOLUMES of all gases under similar conditions of temperature and pressure contain equal number of molecules". Consider two gases distinguished by subscripts 1 and 2. LET `m_(1)` and `m_(2)` =masses of molecules of 1 and 2 respectively. `N_(1) and N_(2)` = no. of molecules of 1 and 2 respectively `P_(1) and P_(2)` = pressure of 1 and 3 respectively `V_(1) and V_(2)` = volumes of 1 and 2 respectively. `P_(1) V_(1) = 1/3 m_(1)N_(1) bar(V_(1)^(2)) and P_(2) V_(2) = 1/3 m_(2)N_(2) bar(V_(2)^(2))` For equal volumes at the same pressure, `P_(1) V_(1) = P_(2) V_(2)` `:. 1/3 m_(1)N_(1) bar(V_(1)^(2)) =1/3 m_(2)N_(2) bar(V_(2)^(2))`_______ (1) If the gases are at the same temperature the average kinetic energies of their molecules are equal. i.e., `1/2 m_(1)bar(V_(1)^(2)) = 1/2 m_(2)bar(V_(1)^(2)) implies m_(1) bar(V_(1)^(2)) = m_(2) bar(V_(1)^(2))` `:.` equation (1) becomes : `N_(1) = N_(2)` Hence, equal volumes of all gases under similar conditions of temperature and pressure have the same number of molecules. |
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| 2492. |
What is the value of least distance of distanct vision for children below 10 years ? |
| Answer» SOLUTION :NEARLY 7 to 8 CM | |
| 2493. |
State whether the following statementare true or false : An electricgeneratorworks on the principleof electromagnetic induction . |
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| 2494. |
What conclusion do you get from the observation that a current-carrying wire deflects a compass placed near it ? |
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Answer» |
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| 2495. |
The wheel shown in the diagram (Fig.1.18) has a fixed axle passing through O. The wheel is kept stationary under the action of (i) a horizontal force F_1 at A and (ii) a vertical force F_2 at B. (a) Show the direction of force F_2 in the diagram. (ii) Which of the force F_1 or F_2 is greater (c) Find the ratio between the forces F_1 and F_2 Given: AO =2.5 cm BO'=1.5 cm and O'O=2.0cm |
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Answer» Solution :The force `F_1` applied at A produces a CLOCKWISE moment on the wheel. It can be balanced by applying the force `F_2` at B in a direction such that it produces an anticlockwise moment. Therefore the VERTICAL force at B should be applied in the downward direction as SHOWN in FIg.1.19 In equilibrium `F_1 times OA=F_2 times OO.` (b) SInce the perpendicular forces `F_1` from O is greater than the perpendicular distanceOO. of point of APPLICATION of force `F_2` from O, so in magnitude, force `F_2` is greater than force `F_1` (c) Moment of force `F_1` about`O= F_1 times OA` (clockwise ) Moment of force `F_2` about `O=F_2 times OO.` (anticlockwise) When the wheel is in equilibrium position, Clockwise moment= Anticlockwise moment i.e., `F_1 times OA=F_2 times OO.` `therefore F_2/F_1= (OA)/(OO.)`........(i) Given OA=2.5 CM and OO.=2.0 cm Substituting the values of OA and OO. in eqn. (i), the ratio of forces `F_2/F_1=2.5/2.0 or F_2:F_1=5:4` 
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| 2496. |
"Wearing helment and fasteningthe seat belt is highly recommendedfor safe jorney". Justify your anwerusing Netwon's laws of motion. |
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Answer» SOLUTION :(i) Whileyou are travellingin a bike or in a car , when a sudden brake is applied , the upper part of your body LEANS in the forward DIRECTION . (ii) Similarly , when the vehicle is suddenly move forward from rest , you LEAN backward. This is due to, any body would like to continue to be in its state of restor the stateof motion . (iii) Newtonslaw of inertiatakes place . So wearinghelmet and seat beltswhile drivinga car are HIGHLY recommendedfor a safe journey . |
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| 2497. |
If a wave of time periodT travels withavelocity V, then the wavelength is given by |
| Answer» ANSWER :B | |
| 2498. |
(a) Define the term absolute refractive index. The absolute refractive index of diamond is 2.42. What is the meaning of this statement ? (b) Refractive indices of media A, B, C and D are given below : {:("Media",A,B,C,D),("Refractive Index",1.33,1.44,1.52,1.65):} In which of these four media is the speed of light (i) minimum and (ii) maximum ? Find the refractive index of medium C with respect to medium B. |
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Answer» Solution :(a) For absolute REFRACTIVE index, see Point Number 23 under the HEADING "Chapter At A GLANCE". For meaning of refractive index of diamond as 2.42. (b) (i) SPEED of light in media D is MINIMUM because its refractive index is maximum. (ii) Speed of light in media A is maximum because its refractive index is minimum. Refractive index of medium C w.r.t. medium B. `n_(CB) = (n_(C))/(n_(B)) = (1.52)/(1.44)=1.06` |
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| 2499. |
Observe the diagram given and aswer the question asked. Sate the reaction of 'E' to different intensity of light. |
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Answer» Solution :1. When a person pass from a brightly lit area to dark room (low intensity of light) the rod shaped cells of retina generate rhodopsin, a pigment that enebles us to SEE in dim light. 2. Conversely, when a person enters a very brightly lit area, th pigment rhodopsin is bleached, REDUCING its sensitivity. |
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| 2500. |
Find electric current draw (figure) from the battery of emf 12V. |
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Answer» Solution :Let `I=I_(1)+I_(2)` be the current drawn from emf 12V. From the FIGURE, using the LOOP law. For the loop DABCD. `-3(I_(1)+I_(2))+12-2I_(1)-5=0.......(a)` for the loop DAFED. `-3(I_(1)+I_(2))+12-4I_(2)=0.......(B)` SOLVING the EQUATIONS (a) and `I_(2)=1.5A` Total current drawn is then I = 0.5 + 1.5 = 2A 
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