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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.
| 1701. |
Which of the following lenses would you prefer to use while reading small letters found in dictionary ? |
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Answer» A CONVEX LENS of focal length 50 cm |
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| 1702. |
A 4 cm tall object is placed on the principal axis of a convex lens. The distance of the object from the optical centre of the lens 12 cm and its sharp image is formed at a distance of 24 cm from it on a screen on the lens, in the which ways (towards the lens or away from the lens) will he have to move the screen to get a sharpimage of the object on it again? How will the magnification of the image be affected ? . |
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Answer» Solution :(a) The screen should be MOVED towerds the LENS to get a sharp IMAGE of the object again. (b) Magnification of the image DECREASES on moveing the object AWAY from the lens. |
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| 1703. |
Experimentally prove that in parallel combination of three resistances: (a) Potential differencr across each resistor is same and (b) Total circuit current is equal to the sum of currents flowing through individual resistors. |
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Answer» Solution :PARALLEL combination of resistors: We take three resistors `R_1,R_2 and R_3` and join them in parallel between the points X and Y. COMPLETE the electric circuit as shown in Fig.12.53. (i) Plug the key and note the ammeter reading I and voltmeter reading V. so, potential difference across the parallel combination of RESISTANCES is V VOLT. (ii) Take out the plug from the key. Remove the ammeter and voltmeter from the circuit. Insert the ammeter A in series with the resistor `R_1` and voltmeter in parallel with the resistors`R_1` (i.e.,across the points L and M as shown in Fig.12.53). Plug the key and note readings of voltmeter and ammeter. Voltmeter reading is even now V but ammeter reading is `I_1`, where `I_1 lt I` (iii) Similarly measure the currents through `R_2 and R_3`. Let these be `I_2 and I_3` respectively. Also measure potential differences across points PQ and ST. Potential differences are found to be V each time. (iv) As voltmeter reading across `R_1,R_2 and R_3` is same as across the parallel combination. we conclude that in parallel combination of resistors. the total potential difference is equal to the potential difference across any one resistor.  (b) Experimentally we find that `I=I_1+I_2+I_3` It proves that in parallel arrangement of resistors the total current is equal to the sum of the currents flowing through individual resistors. 
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| 1704. |
You have two metallic wires of resistances 6 Omega and 3 Omega. How will you connect these wires to get the effective resistance of 2 Omega? |
| Answer» SOLUTION :In PARALLEL because then `1/R=1/6+1/3=(1+2)/3=3/6=1/2` and HENCE `R=2 OMEGA` | |
| 1705. |
Suggest three ways to maintain a balance between environment and development. |
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Answer» Solution :WAYS to MAINTAIN a balance between environment and development to survive are: (i) FOREST resources are to be used in such a MANNER that is both enviromentally and developmentally sound. (ii) By ADOPTING environment friendly technologies and by minimising pollution of natural resources. (iii) By adopting three R.s (Reduce, Reuse and Recycle) which will prevent the early exhausation of natural resources and at same time help in sustainable development. |
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| 1706. |
(a) Describe an activity to show the magnetic field lines formed by a current-carrying circular coil. (b) Draw the magnetic field lines due to current-carrying circular coil. |
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Answer» Solution :(a) Take a rectangular cardboard sheet. Make two holes in it at a suitable distance. INSERT a circular coil having large number of TURNS of ENAMELLED copper WIRE passing through these holes so that the coil is normal to the plane of cardboard. Complete the electric circuit [Fig. 13.20] by joining ends of the coil with a battery and a key K. Sprinkle iron-filings uniformly on the carboard. Plug the key and gently tap the cardboard. The iron-filings arrange themselves along the magnetic field lines. The pattern of iron-tilings gives the magnetic field lines due to current-carrying circular coil. (b) See Fig. 13.4. 
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| 1707. |
Give the construction and working of a solar cooker. |
Answer» Solution :A device that utilises solar energy for cooking purposes is CALLED a solar cooker. The most commonly used form of solar cooker is known as box - type solar cooker is shown in the figure.  CONSTRUCTION of a box - type solar cooker : A box - type solar cooker CONSISTS of the following components: (i) Box (B) : This is an insulated metal or a wooden box. It is pained black from inside because black surface absorbs more heat . The box may be provided with four roll - wheels. (ii) Glass cover (G) : A conver made of two sheets of toughended glass held together in an aluminium frame is used as conver of the box B. (iii) Plane mirror reflector (R) : A plane mirror reflector fixed in a frame is fixed to the box B with the help of hinges . The mirror reflector can be positioned at any desired angle to the box. The mirror is positioned so as to allow the reflected sunlight fall on the glass cover of the box. (IV) Cooking containers (C) : A set containers made of aluminium and blackened from outside are kept in the box B. These containers are also painted black surface absorbs more heat. Working : The food is cooked in a shallow vessel of the container. The box has a transparent covering of glass sheet over it . The solar cooker is placed in sunlight and reflector (plane mirror) is adjusted in such a way that a STRONG beam of sunlight enters the box through the glass sheet. The blackened metal surfaces in the wooden box absorb infra - red radiations from the beam of sunlight and heat produced raises the temperature of blackened metal surface to about `100^@C` The food absorbs heat from the black surface and gets cooked. The thick glass sheet does not allow the heat produced to escape and thus , helps in raising the temperature in the box to a sufficiently high degree to cook the food. |
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| 1708. |
How can you measure torque ? |
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Answer» Solution :It is MEASURED by the productof anyone of the force (F) and the perpendicular distance between the fixed point or the fixed AXISAND the LINE of action of the force . ` TAU = F XX d ` . |
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| 1709. |
Fleming's Right-hand rule gives |
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Answer» MAGNITUDE of the induced CURRENT. |
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| 1710. |
An electric bulb is rated at 60W, 240V. Calculate its resistance. lf the voltage drops to 192 V, calculate the power consumed and the current drawn by the bulb. (Assume that the resistance of the bulb remains unchanged). |
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Answer» <P> Solution :`P=(V^(2))/(R) :. R (V^(2))/(P) = ((240)^(2))/(60W)=960Omega``P= (V^(2))/(R) = ((192)^(2))/(960) = 38.4 W ` `I =(V)/(R)= (192V)/(960Omega)=0.2 A` |
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| 1711. |
Suggest asituastion in which an object is accelerated and have constant speed. |
| Answer» SOLUTION :UNIFORM CIRCULAR MOTION | |
| 1712. |
Elements whose atomic number is less than 83 are undergo spotaneous radioactivity. |
| Answer» SOLUTION :Elements whose atomic NUMBER is more than 83 are undergo spontaneous radioactivity. | |
| 1713. |
Of which physical quantity is the unit,.VA. ? |
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Answer» ELECTRIC ENERGY |
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| 1714. |
What is meant by satellite launch vehicles? Explain a satellite launch vehicle developed by ISRO with the help of a schematic diagram. |
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Answer» Solution :1.SATELLITE launch vehicles are used, to PLACE thesatellites in their specific orbits. The functioning of the satellite launch vehicle is based on the Newton's third law of motion. 2. The structure of the launch vehicle is decided by the weight of the satellite and the type of satellite orbit. Structure of Polar Satellite Launch vehicle (PSLV)developed by ISRO of India. 1.At the top PSLV has a space for satellites. Due to its unmatched reliability, PSLV has also been used to launch various satellites into Geosynchronous and Geostationary orbits, like satellites from the IRNSS constellation. 2.The uppermost stage of PSLV, comprising of two Earth storable liquid engines which USES liquid fuel. 3.The third stage of PSLV is a solid rocket motor that provides the upper stages high THRUST after the atmospheric phase of the launch and it uses a solid fuel. 4.PSLV uses an Earth storable liquid rocket engine for its second stage, known as the Vikas engine. 5.At its FIRST phase, PSLV uses a liquid fuel. 6.At thebottom of PSLV, there is an engine using fuel which provides the initial thrust. 
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| 1715. |
Presently, only "________________" % area of the earth has been left with sensitive spots. |
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Answer» 0.023 |
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| 1716. |
Liquid ammonia is used in ice factory for making ice from water. If water at 20^@C is to be converted into 2 kg ice at 0^@C, how many grams of ammonia are to be evaporated? ( Given: The latent heat of vapourization of ammonia = 341 cal/ g) |
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Answer» Solution :Given:Latent heat of melting of ice =`L_"melt"`=80 cal/G Latent heat of VAPOURIZATION of ammonia = 341 cal/g Temperature of liquid water =`20^@C` Temperature of ice = `T_"ice"=0^@C` Solution:Heat RELEASED during conversion of liquid water into water at `20^@ C , =m_(H_2O) xx L_"melt"` = 2 x 100 x 80 ....(i) Heat released during conversion of water of `20^@`C into ice at `0^@C` `=m_(H_2O) xx DeltaT xxC` = 2 x 1000 x (20 - 0) x 1 = 2 x 1000 x 20 ...(ii) Total heat gained by ice, =(2 x 1000 x 80 ) + ( 2 x 1000 x 20 ) [ from (i) and (ii) ] =2,00,000 cal AMOUNT of ammonia required to be evaporated `m_"Ammonia " xx L_"vap of ammonia " `=2,00,000 `m_"Ammonia"=200000/341`=586.4g 586.4 g of ammonia are to be vaporated . |
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| 1717. |
Which criteria are used for classification of organism ? |
| Answer» Solution :The LIVING organisms are classified according to their basic characteristics , such as presence or ABSENCE of nucleus, unicellular BODY of multicellular body, presence or absence of CELL wall and the MODE of nutrition in them . | |
| 1718. |
Which of the following are renewable and which are non - renewable sources of energy ? Coal, wind , tides , Sun , petrol , biomass , CNG , hydro energy. |
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Answer» Solution :Renewable sources: wind , tides , SUN , biomass, hydro energy Non - renewable sources: COAL , petrol , CNG |
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| 1720. |
Choose the correct option: A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each. |
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Answer» TWO revolutions. |
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| 1721. |
Relative humidity gt 60% : Air is humid : :_______ : Air is dry |
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Answer» |
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| 1722. |
The absolute temperature of the gas is increased 3 times. What will be the increases in root mean square velocity of the gas molecules? |
| Answer» SOLUTION :INCREASES `SQRT(3)` TIMES | |
| 1723. |
The respiratorypigment in human beings is |
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Answer» Carotene |
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| 1724. |
If oneof theprognsofa turningforkgetsbrokenthe vibrations |
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Answer» are maintainedequallywell |
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| 1725. |
State work-energytheorem. Prove it for a variable force. |
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Answer» |
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| 1726. |
Nuclear fusion is more dangerous than nuclear fission. : True or False |
| Answer» SOLUTION :CORRECT Statement: Nuclear FISSION is more dangerous than nuclear fusion. Because the average energy RELEASED in fission (`3.2 x 10^(-11) J`) process is more than the average energy released in fusion (`3.84 xx 10^(-12)J`) | |
| 1727. |
What is Torque ? (or ) moment of force ? |
| Answer» Solution :The rotatingor TURNING EFFECT of a FORCEABOUT a fixed point or fixed AXIS is calledmoment of the FORCE about that point or torque`(tau)`. | |
| 1728. |
What do you mean byearthing ? |
| Answer» Solution :Earthing meansconnecting the metalcase of an ELECTRICAL applianceto the EARTH (at zeropotential ) bymeansofa METAL wirecalledthe earth WIRE . | |
| 1729. |
Draw a schematic labelled diagram of domestic electric circuit. |
Answer» SOLUTION :
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| 1730. |
Explain the role of forests in conserving the environment . How do the forests get depleted ? What are its consequences ? |
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Answer» Solution :Role of forests in conservation of environment : (ii) They provide shelter to WILD animals and are areas that sustain biodiversity. (iii) Theyreduce atmospheric pollution. (iv)They increase humidity and frequency of rainfall. The forests GET depleted due to forestfires , URBANISATION , industrialisation , OVERGRAZING by animals , etc, Theconsequences of deforestation will be : (i)Change in climate and global warming. (ii)Soil erosion and floods (iii)Extinction of wildlife , etc. |
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| 1731. |
Draw the symbols of the following. Ammeter |
Answer» SOLUTION :
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| 1732. |
Use the data in Table 12.2 to answer the following Table 12.2 Electrical - resistivity of some substance at 20^(@)C |
Answer» Solution :  (a) RESITIVITY of iron `=10.0xx10^(-8)Omega` Resistivity of mercury`=9.4xx10^(-8)Omega` (a) Resistivity of mercury is more than that of iron.This implies that iron is a better conductor than mercury. (b) It can be observed from Table 12.2 that the resistivity of SILVER is the lowest AMONG the LISTED materials. Hence, it is the best conductor |
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| 1733. |
A 5 Omega resistor is connected across a battery of 6 volts. Calculate: (i) the current flowing through the resistor. (ii) the energy that dissipates as heat in 10s. |
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Answer» Solution :Here V=6V and R=`5 OMEGA` (i) The current flowing through the RESISTOR `I=V/R=(6V)/(5 Omega)=1.2 A` (II) Energy dissipated as heat in time t=10s is `therefore H=I^2 RT=(1.2)^2 times 5times 10=72 J` |
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| 1734. |
The apparentweightof a person movingupwardin a liftis given by _________ |
| Answer» Answer :C | |
| 1735. |
How much heat should be supplied to convert ice of mass 250 g at 0^(@)C into water at20^(@)C? |
| Answer» SOLUTION :25,000 CAL | |
| 1736. |
A body of mass 0.5 kg travels in straight line with velocity V=ax^(3//2) where a=5m^(-1//2)s^(-1). The work done by the net force durign it's displacement from x=0 to x=2m is |
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Answer» 15 J `W=int_(0)^(2)F ds =50J` |
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| 1737. |
Why are we looking at alternative source of energy ? |
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Answer» Solution :We are looking for alternative SOURCE of ENERGY because Conventional sources of energy 1. like COAL and petroleum are not going to last long. 2. are mostly non-renewable sources of energy. 3. Cause pollution. They are COSTLY. |
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| 1738. |
What are the side effects of watching cartoons and playing mobile games ? |
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Answer» Solution :1. Children who watch cartoon films may imitate the characters of those films. 2. Tendency and behaviour of the children who PLAY the GAMES like virtual war and car reces (especially deliberately brought about virtual acidents in games) gradually become negative. 3. Some games available on cell phones and computers are extremely time-consuming and may also cause enconomic LOSSES, to lose concentration on some essential SUBJECTS and may also PROVE fatal. |
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| 1739. |
The dimensions of action are |
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Answer» `[M L T^(-2)]` `=[M L T^(-2)]` |
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| 1740. |
Which of the following is/are exaple(s) of people. Participation in the management of forests ? |
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Answer» Chipko ANDOLAN |
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| 1741. |
Biogas is produced from bio-matter by : |
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Answer» ANAEROBIC fermentation |
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| 1742. |
Derive an expression for Joule's law of heating. |
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Answer» <P> Solution :P =VI`H=Pxxt=Vt` But `""` V= IR ( Ohm.s LAW ) `:. "" H = I^(2)RT ` |
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| 1743. |
The embryo gets nutrition from the mother's blood with the help of a special tissue called |
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Answer» Zygote |
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| 1744. |
Complete the given folwchart and answer the following questions. i.(##TRG_SCI_TECH_X_P2_C09_E06_011_Q01.png" width="80%"> ii. Give at least two examples of diseases endangering the social health. iii. In which of these factors alcoholic drinks and drugs can be included ? |
Answer» Solution :i.  II. AIDS T.B.Leprosy iii. Alcoholic DRINKS and drugs can be included in Addiction. |
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| 1745. |
Draw neat and labelled diagrams. Steam turbine |
Answer» SOLUTION :
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| 1746. |
On what factors does the resistance of a conductor depend ? |
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Answer» Solution :The resistance R of a conductor DEPENDS on : (1) its LENGTH as Rol (2) its area of CROSSSECTION (1.e.thickness of the conductor) as `R prop 1/A` (3) the nature of the material of the conductor (1.e. RESISTIVITY of material of the conductor) (4) Its temperature |
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| 1747. |
Name some source of direct current. |
| Answer» SOLUTION :SOURCE of pure DIRECT current is a CELL. All others produced fluctuating direct current. | |
| 1748. |
(lungs, heart, carcinogenic, nervous, intoxicating, hazardous, addictions, peer-group, useful) The children fall into the trap of ……………………… either due to …………………………. Pressure or due to false symbol of high standard living. Sometimes they try to imitate their elders. The addictive substances are ......................., and they cause long term effects. Some are temporarily ..................... substances obtained from the plants. While some of the chemical ingredients in them can permanently damage the human ...................... system, muscular system, ......................., etc. Some tobacco like substances are ............................ in action especially on the mouth and ............................. . |
| Answer» Solution :The children fall into the trap of additions EITHER due to peer-group pressure or due to false SYMBOL of high standard living. Sometimes they try to imitate their elders. The ADDICTIVE substances are hazardous, and they cause long term effects. Some are temporarily intoxicating substances obtained from the plants. While some of the CHEMICAL ingredients in them can PERMANENTLY damage the human nervous system, muscular system, heart, etc. Some tobacco like substances are corcinogenic in action especially on the mouth and lungs. | |
| 1749. |
What is difference between compound microscope and Astronomical telescope . |
Answer» SOLUTION :
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| 1750. |
Find the focal length of plano convex lens, when its radius of curvature of the surface is R and n is the refractive index of the lens? |
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Answer» Solution :Len's MAKER formula `IMPLIES (1)/(F)= (n-1)((1)/(R_1) - (1)/(R_2))` `R_1 = OO` ( for plano convex lens ) `R_2 = - R` ( for convex lens ) `implies (1)/(f) = (n-1) (0+(1)/(R ))` `implies (1)/(f) = ((n-1))/(R ) implies f = (R )/((n-1))`. |
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