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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.
| 2251. |
(i) Define electric potential and potential difference.(ii) How does a fuse wire protect electrical appliances? |
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Answer» Solution :Electric Potential : The electric potential at a point is defined as the amount of work done in moving a unit positive charge from infinity to that point against the electric force. Electric Potential Difference: The electric potential difference between two points is defined as the amount of work done in moving a unit positive charge from one point to ANOTHER point against the electric force. (ii)(a) The fuse wire is connected in SERIES, in an electric CIRCUIT. (b) When a large current PASSES through the circuit, the fuse wire melts due to Joule.s heating effect and hence the circuit gets disconnected. (c) Therefore, the circuit and the electric appliances are saved from any damage. (d) The fuse wire is made up of a material whose melting point is relatively low. |
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| 2252. |
When sodiumsulphatesolutionreacts withbariumchloridesolution, thesolutionaftertheractioncontains mainly _____ |
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Answer» bariumsulphate |
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| 2253. |
"Vegetable oils are hydrogenated by additionreaction". Explain this statement with the help of a chemical equation. Why are animal fats not hydrogenated? Out of vegetable oils and animal fats which one is preferred for cooking and why? |
Answer» SOLUTION : `*` Animal fats are saturated. `*` Vegetable oils, because they are GOOD for HEALTH. |
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| 2254. |
n resistors, each of resistances R are first connected in series so as to give an effective resistance R_s Subsequently these resistors are connected in parallel so as to give an effective resistance R_p. Then the ratio R_s/R_p will be |
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Answer» `N:1` In parallel arrangement `1/R_p=1/R+1/R+1/R…. N time s=n/R or R_p=R/n` `THEREFORE R_s/R_p=(nR)/((R/n))=n^2` |
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| 2255. |
The value of acceleration due to gravity on the surface of the moon is 1.625 ms^(-2). |
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| 2256. |
The image obtained while finding the focal length of a convex lens is ……………… . |
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Answer» REAL and ERECT. |
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| 2257. |
The amount of heat required to convert 1 g of ice (specific heat 0.5 cal g^(-1).^@C^(-1)) at -10^@C to steam at 100^@C is |
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Answer» 721 cal |
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| 2258. |
The SI unit of radioactivity is Curie. |
| Answer» SOLUTION :The SI UNIT of RADIOACTIVE is becequerel. | |
| 2259. |
A person's apparent weight insidethe liftincreaseswhen liftis acceleratedupward . |
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| 2260. |
The absolute refractive indices of glass and water are 4/3 and 3/2 respectively. If the speed of light in glass is 2xx10^(8) m/s calculate the speed of light in (i) vacuum(ii) water. |
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Answer» SOLUTION :Since, refractive index of glass `=("SPEED of light in cavuum" (v))/("Speed of light in glass(n)")` `c=v/n` `4/3=v/(2xx10^(8))` `v=4/3xx2xx10^(8)` `=8/3xx10^(8)=2.6xx10^(8)m//s` `v=3xx10^(8)m//s` Refractive index of water `=("Speed of light in VACUUM")/("Speed of light in water")` `n=v/w` `w=v/n=(3xx10^(8))/3` `=(cancel(3)xx10^(8)xx2)/(cancel(2))=2xx10^(8)m//s` |
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| 2261. |
Define Linear Momentum . |
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Answer» Solution :The PRODUCT ofmass and velocity of a moving body GIVES the magnitudeof LINEARMOMENTUM . Itacts in the direction of the velocity of the object . Linear MOMENTUM = mass ` xx ` velocity p=mv |
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| 2262. |
Planck's constant h, speed of light c and gravitational constant G are used to from a unit of length L and a unit of mass M. Then the incorrect option is |
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Answer» `M PROP SQRTC` |
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| 2263. |
An object is placed at a distance of 60 cm from a concave lens of focal length 30 cm. (i) Use lens formula to find the distance of the image from the lens. List four characteristics of image (nature, position, size, erest/inverted) formed by the lens in this case. (iii) Draw ary diagram to justify your answer of part (ii). |
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Answer» Solution :`u = -60cm,F = -30 cm` (i) Lens FORMULA, `1/f = 1/V - 1/u` `1/v = 1/f +1/u` `rArr 1/v=1/-30+1/-60=(2+1)/-60=3/-60` `v=(-60)/3 =-20cm `The image is at a distance of 20 cm from the lens. (ii) Characteristics of image formed. The image is - `{:(" vortual,", erect,",in front of the lens between 'O' and 'F',"),(" on the same side of the object, and ","","diminished."):}` (III) 
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| 2264. |
Is it possible to increase the temperature of a gas without giving it heat? OR Name the process, in which no heat is transfereed tofrom a system but the temperature of the system changes. |
| Answer» SOLUTION :YES, it happens during an ADIABATIC PROCESS. | |
| 2265. |
What happens when ferrous sulphate crystals are heated? |
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Answer» Solution :When ferrous sulphate crystals are heated, the colour changes from green to white because of dehydration and then a brown solid of ferric oxide is formed with the smell of burning SULPHUR. `UNDERSET(("Green"))(FeSO_(4)).7H_(2)Ooverset("Heat")(to)underset(("White"))(FeSO_(4))+7H_(2)O` `2FeSO_(4)OVERSET("Heat")(to)Fe_(2)O_(3)+underset(("Brown"))(SO_(2))+SO_(3)` |
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| 2266. |
Distinguish between Butterfly and Bat: |
Answer» SOLUTION : 
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| 2268. |
Define geotropism. Draw a labelled diagram of a plant showing geotropic movements of its parts. |
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Answer» Solution :PLANTS show tropism in response to other stimuli as well. The roots of a plants always grow downwards while the shoots usually grow upwards and away from the Earth this upward and DOWNWARD growth of shoots and roots ,respectively, in response to the pull of earth or gravity is called geotropism. If we KEEP the potted plant horizontally for 2-3 days, shoots grow upwards and away from the Earth while growth of roots is directed in downward direction . This occurs as shoots are POSITIVELY phototrophic and negatively geotropic while roots are positively geotropic in nature. 
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| 2270. |
(a) State Fleming's left hand rule. (b) Write the principle of working of an electricmotor. (c ) Explain the function of the followingparts of an electricmotor. (i) Armature , (ii) Brushes , (iii) Split ring |
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Answer» Solution :(a) Fleming's left hand rule, Accordingto Fleming's left hand rule, hold the forefinger, the centre FINGER and the thumb of your left hand atright anglesto one another. Adjustyour hand in such a waythat the forefingerpoints in the direction of magneticfieldand the centrefinger pointsin the direction of forceacting on the conductor. (b) Principle of anelectric motor. The workingprincipleof an ELECTRICMOTOR is based onthe magenticeffectof current. An electricmotorworkson the principlethat when a rectangularcoil isplacedin a magnetic fieldand currentis passed through it, a forceacts onthe coil whichrotates it continuously. It is based on Fleming's lefthand rule. (c ) (i) Armature . It is the rotating part ofa motor. Armatureis a coil whichcarries currentand rotates in the magenticfield. (ii) Brushes. The function of carbon brushes is to make contact with the rotatingsplit-ringsof the commutatorso as to supply currentto the coil. (iii) Spilt ring.The function of SPLIT rings is to REVERSE the direction of currentflowingthroughthe coil everytime the coil passes the vertical positionduring a REVOLUTION. |
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| 2271. |
The act based on which the National Disaster Response Force has been established. |
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| 2272. |
The radius of gold nucleus is 41.3. fermi. Express its volume in m^3 |
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Answer» `2.75xx10^(-20) m^3` |
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| 2273. |
What are the effects of electrical energy generation on environment? Are fossil fuels a good way of electric energy generation? |
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Answer» Solution :The energy obtained through the fossil fuels as well as nuclear energy can cause degradation of the environment. If such energy sources are used, they can cause harm to the environment. (1) The burning of fossil fuels air pollution. The incomplete combustion of fossil fuels cause release of carbon monoxide. Some more toxic gases and soot particles cause various respiratory diseases. The carbon dioxide produced is CREATING global warming and climate change. The nitrigen dioxide released through burning is responsible for acid rains. (2) Fossil fuels are limited. They are getting fast DEPLETED. It has taken millions of years for the fossil fuels to form. The exploration of such fuels also cause environmental degradation and marine pollution too. (3) In production of nuclear energy, there is a great risk of accidents. The safe disposal of nuclear WASTE is also a problem. (4) Hydroelectric power from water reservoirs, WIND power from wind, solar energy from sun and electricity from BIOFUELS are eco-friendly alternatives. |
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| 2274. |
A ray of light travelling in air enters obliquely into water. Does the light ray bend towards the normal or away from the normal? Why? |
| Answer» Solution :TOWARDS the NORMAL because speed of LIGHT decreases when it goes from air (rarer medium) into water (DENSER medium). | |
| 2275. |
Which of the following circuits will still be dangerous even if the fuse blows off and electric iron stops working during a short circuit ? |
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| 2276. |
Two copper wires A and B have the same mass. The resistance of wire A is 0.5Omega and the length of wire B is double that of wire A. Find the resistance of wire B. |
| Answer» SOLUTION :`2 OMEGA` | |
| 2277. |
The regions in the crust where the hot magma is collected are called |
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| 2278. |
What is the heating effect of electric current? |
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Answer» Solution :When an electric current is passed through a HIGH RESISTANCE wire, like Nichrome wire, then the.resistance wire becomes very hot and produces heat. In purely RESISTIVE circuits, the source energy continually gets dissipated entirely in the form of heat. This is known as the heating EFFECT of electric current. Heating effect of electric current, 1.e., conversion of electrical energy into heat energy is utilised in devices such as electric heater, electric iron, etc. |
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| 2279. |
Annelida : Earthworm : : Platyhelminthes : ……. |
| Answer» SOLUTION :Planaria/Liverfluke | |
| 2280. |
-C-OH is called…………… |
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Answer» CARBOXYLIC ACID group |
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| 2281. |
Explain with diagram step-by-step energy conversion in Hydroelectric power plant |
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Answer» Solution :a. In a hydroelectric power plant , water RESERVOIR is used as the source of energy. b. CONVERSION of potential energyt from water to KINETIC energy:The potential energy in water stored in a water reservoir like a dam is converted to kinetic energy of water by making it flow to the bottom of the dam. c. Conversion of kinetic energy in water to kinetic energy in turbine:FAST flowing water is brought from the dam to the turbine at the bottom of the dam. The kinetic energy of the flowing water drives the turbine. d.Conversion of kinetic energy in turbine toelectrical energy:The turbine rotates the generator connected to it which in TURN produces electrical energy. 
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| 2282. |
If the speed of a car is halved, how does its kinetic energy change? |
| Answer» SOLUTION :It BECOMES one-fourth | |
| 2283. |
State the rules to draw a ray diagram of a convex lens with proper figures. |
Answer» Solution :i. Rule I: When the incident ray is parallel to the principal axis, the REFRACTED ray PASSES through the principal FOCUS.  ii. Rule II: When the incident ray passes through the principal focus, the refracted ray is parallel to the principal axis.  iii. Rule III: When the incident ray passes through the OPTICAL centre of the lens, it passes without CHANGING its direction. 
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| 2284. |
The non-renewable source of energy among the following is : |
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Answer» HYDROELECTRICITY |
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| 2285. |
A particle moves in a circular path with decreasing speed. What happens to its angular momentum ? |
| Answer» Solution :as `vecL = vecr XX m vecv` i.e. magnitude `vecL` DECREASES but direction REMAINS CONSTANT. | |
| 2286. |
Down's syndrome is the genetic condition with 45 chromosomes. |
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Answer» 44 |
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| 2287. |
List the three phenomena of light responsible for the formation of rainbow in the sky. |
| Answer» SOLUTION :(i) Refraction, (II) DISPERSION, and (iii) INTERNAL reflection of light. | |
| 2288. |
Name the component of while light that deviates the least and the most while passing through a prism. |
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Answer» SOLUTION :(i) Least deviation : RED. (ii) Maximum deviation : VIOLET. |
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| 2289. |
Give two uses of a magnetic compass. |
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Answer» SOLUTION :i] In PLOTTING the MAGNETIC field of a barmagnet . ii] In SHIPS and jetliners to aid in NAVIGATION. |
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| 2290. |
Name the reaction responsible for the large energy production in the sun. |
| Answer» SOLUTION :NUCLEAR FUSION | |
| 2291. |
Three mass points each of mass m are placed at the vertices of an equilateral tringale of side l. What is the gravitational field and potential due to three masses at the centroid of the triangle ? |
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Answer» Solution :`E_1= (GM)/((OA)^2)` `E_2= (GM)/((OB)^2)` `E_3= (GM)/((OC)^2)`  From `triangleOBD, ""cos 30^(@)= (BD)/(OB)=(l"/"2)/(OB)` `OB= (l"/"2)/(cos 30^(@))= (BD)/(OB)= (l"/"2)/(2sqrt(3))= l"/"sqrt(3)` Gravitational field at O due to m at A, B and C is say `vec(E_1), vec(E_2)" and " vec(E_3)`. `E= sqrt(E_(2)^(2)+E_(3)^(2)+2E_(2)E_(3) cos 120^(@))` `=sqrt(((GM3)^2)/(I^2)+((3Gm)/(I))^2+2((3GM)/(I))(-(1)/(2)))` `=(3GM)/(I)=` along OD `vecE` is equal and opposite to `vec(E_1)` net gravitational field = zero As gravitational potential is scalar `V ""=V_(1)+V_(2)+V_(3)` `=(GM)/(OA)-(GM)/(OB)-(GM)/(OC)` `V""= -(3GM)/(I"/"sqrt(3))= -3sqrt(3)(Gm)/(I)`. |
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| 2292. |
Which law is used in geotropism ?: |
| Answer» SOLUTION :NEWTON's LAW of GRAVITATION. | |
| 2293. |
Which one of the following is responsible for the sustenance of underground water ? |
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Answer» Loss of VEGETATION cover |
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| 2294. |
A nuclear reaction is represented by the equation :._(1)^(2)H + ._(1)^(2)H rarr ._(2)^(3)He + xc + E(a) Name the process represented by this equation and describe what happens during this reaction.(b) Identify the particle c and the number x of such particles produced in the reaction. (c ) What does E represent ? (d) State two conditions under which such a reaction takes place.(e) What type of nuclear bomb is based on similar reactions ? |
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| 2295. |
At what angle do the two forces (P + Q) and (P – Q) act so that the resultant is sqrt(3P^(2)+Q^(2)). |
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Answer» Solution :Use`R= sqrt(A^(2)+B^(2)+2AB COS Q)` `R=sqrt(3P^(2)+Q^(2)), A=P+Q`, `B=P-Q` solve, `theta=60^(@)` |
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| 2296. |
My body is radially symmetrical . Water vascular system is present in my body . I am referred as fish though I am not. What ismy name ? |
| Answer» SOLUTION :STARFISH. I am from ECHINODERMATA PHYLUM. | |
| 2297. |
Name the type of nuclear reaction which is involved in the working of :(a) a hydrogen bomb.(b) an atom bomb. |
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| 2298. |
State Newton's third law. Explain it with three examples. |
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Answer» SOLUTION :Newton.s third law of motion : Newton.s third law states that .for every action, there is an equal and opposite reaction. They always act on two different bodies.. If a body A applies a force `F_(A)` on a body B, then the body B reacts with force `F_(B)` on the body A, which is equal to `F_(A)` in magnitude, but opposite in DIRECTION. `F_(B)=- F_(A)` Examples: (i) When birds fly they push the AIR downwards with their wings (Action) and the air pushes the bird upwards (Reaction). (ii) When a person swims he pushes the WATER using the hands backwards (Action), and the water pushes the swimmer in the forward direction (Reaction). (iii) When you fire a bullet, the gun recoils backward and the bullet is moving forward (Action) and the gun EQUALISES this forward action by moving backward (Reaction). |
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| 2300. |
A bullet fired in to a fixed target tosses half of it's velocity after penetrating distance of 3 cm. How much further it will penetrate before coming to rest assuming that if faces constnat resistance to it's motion? |
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Answer» 3 cm Case I: `Fxx3=1/2m((V_(0))/2)^(2)-1/2 MV^(2)` Where `Fto` resistive force `V_(0)to` initial VELOCITY Case II: Let further distance be s `-F(3+s)=K_(f)-K_(i)=-1/2 mV_(0)^(2)` `S=1cm` |
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