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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.
| 5001. |
12 V, 9 V and 12 V bulbs are connected in series. What is the potential difference of their combination ? |
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Answer» Solution :1. `V_(C)=V_(1)+V_(2)+V_(3)` 2. `V_(c)=12V+9V+12V` 3. `V_(c)=33V` Potential Difference of their COMBINATION is 33 V. |
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| 5002. |
The potential difference required for the flow of charges is provided by the voltmeter. |
| Answer» Solution :The potential difference REQUIRED for the FLOW of charges is PROVIDED by the BATTERY. | |
| 5003. |
Mention the conditi.on under which charges an move in a conductot Name the device which is used to maintain this condition in an electric circuit |
| Answer» SOLUTION :CHARGES can move if there is a difference of electric pressure or potential difference ALONG the conductor. Electric cell or a BATTERY consisting of TWO or more -cells. | |
| 5004. |
What is the speed of the car at the instant of time 't_(3)' for given motion ? |
Answer» SOLUTION : The instantaneous speed is represented by the slope of the curve at a given instant of time. We can FIND the slope of the curve at any point on it by drawing a TANGENT to the curve at that point. The slope of the curve gives speed of the CAR at that instant. |
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| 5005. |
At the uppermost point of a projectile, its velocity and acceleration are at an angle of |
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Answer» `0^(@)` |
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| 5006. |
Which expansion coefficient (alpha, beta, gamma) of a substance has largest and y smallest magnitude? |
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Answer» `alpha, BETA` |
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| 5007. |
If the image formed by a sphericalmirror for all positions of the object placed in front of its is alwayserect and diminished , what type of mirror isit ? Draw a labelledray diagramto supportyour answer. |
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Answer» Solution :It is a convex MIRROR. Convex mirror always from erect,virtualand DIMINISHED IMAGE forall POSITIONS of the object placedin frontof it . It is a convex mirror. DIAGRAM : 
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| 5008. |
Name the main constituent of biogas. |
| Answer» Solution :The MAIN CONSTITUENT of BIOGAS is METHANE (75%) | |
| 5011. |
The frequency of vibration of a string depends of on, (i) tension in the string (ii) mass per unit length of string, (iii) vibrating length of the string. Establish dimensionally the relation for frequency. |
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Answer» SOLUTION :`npropI^(a)T^(B)m^(c),[I]=M^(0)L^(1)T^(0)` `[T]=M^(1)L^(1)T^(-2)` (force) `[M]=M^(1)L^(-1)T^(0)` `[M^(0)L^(0)T^(-1)]=[M^(0)L^(1)T^(0)]^(a)[M^(1)L^(1)T^(-2)]^(b)[M^(1)L^(-1)T^(0)]^(c)` `b + c = 0` `a + b – c = 0` `-2b=-1impliesb=(1)/(2)` `c=-(1)/(2)a=1` `nprop(1)/(l)sqrt((T)/(m))` |
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| 5012. |
Draw a diagram to show the formation of image of a distant object by a myopic eye. How can such an eye-defect be rectified? |
Answer» Solution :DIAGRAM.  It can be RECTIFIED by using CONCAVE LENS. |
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| 5013. |
Most of the disasters and related unprecedented situations of the world have happened in the Asian continent and region of Pacific Ocean. |
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Answer» |
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| 5014. |
Make a table based on forms of energyand corresponding devices. |
Answer» SOLUTION :
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| 5015. |
An object is kept 15 cm in front of a concave lens of focal length 20 cm. If the object is moved by 3 cm towards the lens, by what factor will the magnifiation change ? |
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Answer» 20/19 |
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| 5016. |
What is heating effect of current? Mention any two of its applications. |
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Answer» Solution :When current flows through a conductor, HEAT energy is generated in the conductor. This is called heating EFFECT of electric current. Two applications of this effect are: i] Electric bulb: Electric current heats up the filament of the bulb which then glows emitting light ii] Electric fuse: When a high current flows through a fuse, its wire gets HEATED and melts breaking the CIRCUIT and PROTECTING appliances. |
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| 5017. |
The phenomenon of nuclear decay of certain elements with the emission of radiations likealpha, beta, "and" gamma ray is called __________. |
| Answer» SOLUTION :RADIOACTIVITY | |
| 5018. |
An electric heater of resistance 8 Omega draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater. |
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Answer» Solution :`R= 8 Omega I = 15 A t, = 2h =2 xx60 xx60 s ` `H= I^(2) Rt = (15)^(2) xx8xx2xx60xx60` Rate at which HEAT PRODUCED :` = (H)/(t)` `= (15^(2)xx8xx2xx60xx60)/(2xx60xx60)` = 1800 W |
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| 5019. |
Fill in the blanks to complete the following sentence: Q: The refractive index of glass with respect to air is 3/2. thee refractive index of air with respect to glass will be _____ |
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| 5020. |
In which defect of vision is (i) the far point nearer than infinity ? (ii) near point away from 25 cm ? |
| Answer» SOLUTION :(i) MYOPIA (II) HYPERMETROPIA. | |
| 5021. |
Two conducting wires of the same materialand of equal lengths and equal diameters 1 are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced inseries and parallel combinations would be- |
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Answer» Solution :As both the wires are made of the same material and are of EQUAL lengths and equal diameters. they have the same resistance R. When they are CONNECTED in series their equilvalent resistance `R_s` would be - `R_s = R + R = 2R` and when they are connected inparallel their equivalent resistance `R_p`is given by `1/R_p = 1/R + 1/R =2/R` `:. R_p =R/2` Now. heat produced in time t is `H = (V^2t)/(R)`. As here source voltage V is same, when wires are conncted in series, `H_s = (V^2t)/(R_s) = (V^2t)/(2R)` When wires are connected in parallel, `H_p =(V^2t)/(R_p) =(V^2t)/(R/2) = (2V^2t)/R` `:.` The RATIO of heat produced, `H_s/H_p = (V^2t)/(2R) xx R/(2V^2t) = 1/4` `:. H_s : H_p= 1: 4` |
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| 5022. |
Match the Column {:("(1) Ciliary muscles","(a) Concave lens in used to correct"),("(2) Cataract","(b) Old age eye defect"),("(3) Myopia","(c) adjust the focal length of eye lens"),("(4) Presbyopia","(d) Development of an opaque layer over eye lens"):} |
| Answer» SOLUTION :1. (C) 2. (d) 3. (a) 4. (B) | |
| 5023. |
An object 4 cm in height, is placed at 15 cm in front of a concave mirror of focal length 10 cm. At what distance from the mirror should a screen be placed to obtain a sharp image of the object. Calculate the height of the image. |
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Answer» Solution :Here distance of object u = - 15 cm, height of object h = +4 cm and the focal length of CONCAVE mirror f = - 10 cm. As per mirror formula `(1)/(v) + (1)/(u) = (1)/(f)`, we have `(1)/(v) = (1)/(f) - (1)/(u) = (1)/((-10)) - (1)/((-15)) = - (1)/(30) RARR v = - 30` cm. Thus, a screen be placed infront of mirror at a distance of 30 cm from it. `because` magnification `m = (h.)/(h) = - (v)/(u)` `therefore ""h. = - (v)/(u) xx h = - ((-30))/((-15)) xx 4 = - 8` cm Thus, image is an inverted image of height 8 cm. |
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| 5024. |
(i) What are the characteristic features of heat energy transfer? (ii) Explain linear expansion with diagram? |
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Answer» Solution :• Heat always flows from a system of higher temperature to a system at lower temperature. . The mass of a system is not ALTERED when it is heated or cooled. • Heat gained by the cold system is equal to heat lost by the HOT system. (ii) • When a body is heated or cooled,the length of the body CHANGES due to change in its temperature. • Then the expansion is said to be on linear or longitudinal expansion. • The ratio of increase in length of the body per degree rise in temperature to its unit length is called as the coefficient of linear expansion. • It is different for different materials. Its SI unit is `K^(-1)` • The EQUATION is `(DeltaL)/(L_(0))=alpha_(L)DeltaT` `DeltaL`- Change in length (Final length - Original length) `L_(0)` - Original length (Final temperature - Initial temperature) `alpha_(L)` -Coefficient of linear expansion 
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| 5025. |
A bulb is rated at 200V -40W. What is its resistantt ? 5 such bulbs are lighted for 5 hours. Calculatethe electrical energy consumed ? Find the cost if the rate is 5.10 per KWh. |
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Answer» SOLUTION :V = 200 V,P = 40 W P =VI `I=(P)/(V) =(40)/(200) = (1)/(5)` A `R= (V)/(I) = (20)/((1)/(5))` `=200xx5=1000 Omega` Total power `=40Wxx5=200W` Time =5 hrs ELECTRICAL energy `= 200 Wxx5 hrs` =1000 Wh = 1 KWh. Cost of 1 Kwh = 5.10 RS. |
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| 5026. |
What type of image the convex mirrors make? |
| Answer» Solution :CONVEX mirrors always MAKE a virtual, erect and small SIZE image in size for any POSITION of the object. | |
| 5027. |
Explain in detail hotspots of biodiversity. |
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Answer» Solution :i. Biodiversity hotspots are the geographical areas with high species diversity which need maximum protection. II. Around 34 highly sensitive biodiversity spots are reported all over the worl. Currently, only 2.3% area of earth has been LEFT with the hotspots. III. Biodiversity hotspots onc occupied 15.7% area of the earth but at present 86% of these sensitive areas are already destroyed. iv. Biodiversity hotspot include 1,50,000 plant species accounting to 50% of the world count. v. In India , out of 135 species of animals, 85 species are FOUND in the jungles of eastern region. Around 1,500 endemic plant species are found in Western Ghats.Also, out of the total plant species in the entire world 50,000 are endemic. |
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| 5028. |
What will you do? Why? Your brother studying in XII has developed stress. |
| Answer» Solution :I will TALK to my brother and EXPLAIN him that he can raduce his stress by EXERCISE, YOGA, walking or SPENDING some time with his friends. Also, I will tell him the importance of planning as imporper planning leads to stress. | |
| 5029. |
Tell me who am I ? What is my class/phylum ? My body is divided into proboscis , collar and trunk . I am marine animal . |
| Answer» SOLUTION :BALANOGLOSSUS : PHYLUM : HEMICHORDATA. | |
| 5030. |
A convex lens behaves as a converging lens but a concave lens behaves as a diverging lens. |
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| 5031. |
Explain the construction and working of an electric motor. Draw a neat diagram and label it. |
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Answer» Solution :Figureshows the construction of an AC electric generator. Here, a coil ABCD of copper wire is kept between the pole pieces (N and S) of a strong magnet. The ends of the coil are CONNECTED tothe conducting rings `R_(1), and R_(2)`, via CARBON brushes `B_(1) and B_(2)`. The rings are fixed to the axle and there is a resistive coating in between the rings and the axle. The stationary brushes are connected to a galvanometer used to show the direction of the current in the circuit. Working : When the axle is rotated with a machine from outside, the coil ABCD starts rotating. Suppose the coil rotates in clockwise direction, as observed from the side AD. Then as the branch AB moves UPWARD, the branch CD moves downward. By Fleming's right hand rule, the induced current FLOWS in the direction `A to B to C to D` and in the external circuit, it flows from `B_(2)` to `B_(1)`, through the galvanometer. The induced current is proportional to the number of turns of the copper wire in the coil. After HALF a rotation, AB and CD interchange their places. Hence, the induced current flows in the direction `D to C to B to A`. As AB is always in contact with `B_(1)`, and CD is in contact with `B_(2)`, the current in the external circuit flows from `B_(2)`, to `B_(2)`, through the galvanometer. Thus, the direction of the current is the external circuit is opposite to that in the previous half rotation. The process goes on repeating and alternating current is generated. 
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| 5032. |
Say True or False.At the poles, the acceleration due to gravity is 9.77m//s^(2) |
| Answer» Solution :FALSE. The acceleration DUE to GRAVITY is `9.83m//s^(2)` at the POLES. | |
| 5034. |
Explain with diagram step-by-step energy conversion in: Power plant based on wind energy : |
Answer» SOLUTION : WIND ENERGY is used for MOVING turbines. The wind with specific speed is used to rotate the large fins of wind turbine. The kinetic energy in these fins is TRANSFERRED to generator which then produces electrical energy. |
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| 5035. |
What is clean technology? |
| Answer» Solution : Clean TECHNOLOGY is the METHOD to use microbes for controlling AIR, soil and WATER POLLUTION. These microbes can degrade the manmade chemicals. | |
| 5036. |
Whatare the effect of intoxicating drugs? |
| Answer» Solution :Temporarily intoxicasting drugs of PLANTS ORIGINS and some chemical may permanently DAMAGE the human nervous system, MUSCULAR system, HEART etc. | |
| 5037. |
List two main advantages of solar cells. |
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Answer» Solution :(i) They have no moving parts and REQUIRE little maintanence. (II) They can be SET up even in REMOTE areas. |
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| 5038. |
What is scattering ? |
| Answer» Solution :ATOMS or molecules which are EXPOSED to absorb light energy and EMIT some part of the light energy in different DIRECTIONS is called SCATTERING of light. | |
| 5039. |
Is similar force acting on them? What must be its direction |
| Answer» Solution :The other planets REVOLVE around the sun in the similar fashion due to the centripetal force EXERTED on them by the sun. The DIRECTION of the force is towards the CENTRE of the sun . | |
| 5040. |
Stars twinkle while the planets do not. Why? |
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Answer» Solution :Continuously changing atmosphere REFRACT light from the stars by different amounts from one MOMENT to the other. When atmosphere refracts more starlight towards us, the stars APPEARS to be bright and when the atmosphere refracts less starlight, then the stars appear to be dim. However the PLANETS are nearer to us than the stars, they appear to be comparatively bigger to us so they cannot be CONSIDERED as a point source, hence no twinkling is seen. |
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| 5041. |
Draw a labelled diagram of an electric motor. Explain its principle and working. What is the function of a split ring in an electric motor ? |
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Answer» <P> Solution : Principle : A current - carrying conductor, when placed in a MAGNETIC field. Experiences a force. If the DIRECTION of the field and that of the current are mutually perpendicular to both and will be given by Fleming.s left hand rule due to this force the conductor begins to move. Working : Current in the coil ABCD enters from the source battery through conducting brush X and flow back to the battery through brush Y, The current in arm AB of the coil flows from A to B, In arm CD it flows C to D, that is opposite to the direction of current through arm AB We find that force acting on arm AB pushes it DOWNWARDS while the force acting on arm CD pushes it upwards Thus the coil and the axle O, mounted FREE to turn about an axis, rotate anti-clockwise, At half rotation, Q makes contact with the brush X and P with brush Y. Therefore the current flows along the path DCBA, The reversal of current also reverses the direction of force acting on the two arms AB and CD. Thus the arms AB of the coil that was earlier pushed down is now pushed up and the arm CD previously pushed up in now pushed down, Therefore the coil and the axle rotate half a turn more in the same direction. The reversing of the current is repeated in each half rotation giving rise to a continuous rotation of the coil and the axle. The split rings help to reverse the direction of current in the circuit, there are called the commutator. |
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| 5042. |
Define the following terms in the context of spherical mirrors :(i) Pole(ii) Centre of curvature(iii) Radius of curvature(iv) Principal axis(v) Principal focus |
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Answer» Solution :(i) Pole : The centre of the reflecting surface of a spherical mirror. (ii) Centre of curvature : The reflecting surface of a spherical mirror is PART of a sphere. The centre of that centre of that sphere is called centre of curvature. (iii) Radius of curvature : The radius of the sphere from which a mirror is made. (iv) Principal AXIS : An imaginary line passing through the pole and the centre of curvature. The principal axis is NORMAL to the mirror at the pole. (v) Principal focus : The point on the principal axis, at which incident light rays PARALLEL to the principal axis converge or appear to diverge froms, is called the principal focus of the lens. |
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| 5043. |
A projectile is fired with kinetic energy 1 kj. If itsrange is maximum, what will be its kinetic energyat the highest point of its trajectory ? |
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Answer» Solution :here `(1)/(2) mv^(2)=1|KJ=1000J, THETA=45^(@)` At the highest POINT, K.E. `=(1)/(2) m(V cos theta)^(2)=(1)/(2)(mv^(2))/(2)=(1000)/(2)=500J`. |
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| 5044. |
Acetic acid when dissolved in water, it does not dissociate completely. Why ? |
| Answer» SOLUTION :As ACETIC ACID is a WEAK acid and in its aqueous solution it is not completely ionised into its ions. | |
| 5046. |
A combination of two ……….. Lenses is used in telescops. |
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Answer» concave |
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| 5047. |
The angle between the two refracting surfaces of a total reflecting prism is |
| Answer» ANSWER :A | |
| 5048. |
Thesolutionof Al_(2)(SO_(4))_(3)in water is______. |
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Answer» Bluein COLOUR |
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| 5049. |
What is the reaction called when oxidation and reduction take place simultaneously ? Explain with one example. |
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Answer» Solution :The REACTION whichinvolvessimultaneous oxidation and reduction is called an oxidation-reduction or redox reaction. In a redox reaction, one reactant gets oxidised while the other gets reduced during a reaction. Redox reaction = Reduction + Oxidation In redox reaction, the reductant is oxidised by the oxidant and the oxidant is reduced by the reductant. Example : `CuO_((s)) + H_(2(g)) + H_(2)O` In this reaction, oxygen is removed from copper oxide therefore it is a reduction of CUO, while hydrogen accepts oxygen to form water that means oxidation of hydrogen take place. THus oxidation and reduction reactions occur simultaneously. Other examples of redox reactions : `underset("Hydrogen")(2H_(2)S) + underset("sulphide")(SO_(2)) tounderset("SULPHUR")(3S) + 2H_(2)O` `underset("Manganese dioxide")(MnO_(2))+4HCl to underset("Manganese CHLORIDE")(MNCl_(2))+2H_(2)O+Cl_(2)uparrow` |
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| 5050. |
Define magnetic field of a bar magnet. |
| Answer» SOLUTION :It is the REGION AROUND the MAGNET in which FORCE due to magnet can be felt. | |