This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Why is the value of 'g' 0 at the centre of the earth???? |
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Answer» at the CENTRE of the earth the mass under consideration reduces to finally become zero.so put the value of M in the formula of SMALL'G' and you will get the value of SAMLL g as 0 |
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| 2. |
A person clapped his hand near a cliff and hurt the echo after 5 sec. what is the distance of the cliff from the person if the speed of the sound v is taken as 340m/s |
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Answer» ere's your answer......The SOUND traveled from the PLACE the person STOOD, to the cliff and then REBOUNDED back to the person , so the person heard the resound/echo.So the sound traveled TWICE the distance between him/her and the cliff.Distance between cliff and person = 340 m/sec * 5 seconds / 2 = 850 metersThanks...!!!XDSorry baby 'wink' |
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| 3. |
With referce to sound what you meanby frency wave length and echo |
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Answer» frequency and wavelength with reference to sound. ... Wavelength The MINIMUM distance in which a SOUNDWAVE repeats itself. Echo The REPETITION of sound caused by reflection of sound waves is CALLED anecho. Full form of SONAR is SoundNavigation and RANGING. |
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| 4. |
the two bodies have their masses M1 /M2 = 1 and their kinetic energy is given by K.E1/K.E2 1/ 2 the ratio of their velocities is |
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Answer» k1/k2=1/3 =(1/2)m1v1²/(1/2)m2v2²=1/3= m1/v1²/m2v2²=1/3But,(m1/m2=3)=3(v1/v2)²=1/3=(v1/v2)²=1/9=v1/v2=(1/9)½=1/3 |
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| 5. |
A ball is thrown vertically upword with a speed of 120m/s.it speed at mid point of iths path about |
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| 6. |
Derive an expression for conductivity of conductor in terms of relaxartion time |
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Answer» ing solid, an electron will suffer collisions with fixed heavy ions. After collisions,electron will emerge with same speed, but direction changes RANDOMLY. If we considerN number of electrons in a given volume, since directons are changed randomly due to collisions,average VELOCITY of N electrons will be zero.This is expressed as .................(1)If electrons are accelerated by electric field E, then acceleration is given by, a = -eE/m ..........(2) Let us consider an ith electron in a group of N electrons at a given time t.Let us assume after a previous collision, speed of this ith electron is vi and there is an elapsed time ti after collision. Speed Vi of this ith electron at time t is given by, Vi = vi - (eE/m)ti ...............(3) Average velocity of electrons at time t is average of all Viof each electron in the group we have considered.In eqn.(3), average of vi appearing on left side is zero as mentioned in eqn.(1).Collisions of elecrons do not occur at regular intervals but at random time. Let us DENOTE the averagetime between successive collisions as τ. Then averaging eqn.(3) over N electrons at any given time t gives us average velocity vd, as given byvd............................(4)vd is called drift velocity. Due to drift, there will be net transfer of charges across any area perpendicular to Electric field E. Consider a planar area A, LOCATED inside the conductor such that normal to area is parallel to Electric filed E.Then because of drift, in an infinitesimal amount of time Δt, all electrons to the left of the area at distancesupto |vd|Δt would have crossed the area. If n is number of free electrons per unit volume in the metal,then there are nΔt|vd|A such electron. Since each electron carry a charge -e, the total charge transportedacross this area A to the right in time Δt is -neA|vd|Δt. Flow of charge per unit time across an area A is the magnitude of current I.Then we have, I = neA|vd| ..................(5)by substituting vd from eqn.(4) in eqn.(5),  ..............................(6)Current density J is defined as, J = I/A, where I is the current flowing in a cross section area A. hence eqn.(6) is written as, J = σE, where conductivity σ is expressed as  |
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| 7. |
Explain, insulator, semiconductor and conductor in terms of band gap |
| Answer» SEMICONDUCTORS, there is a band gap, but compared to insulators it is so small that EVEN at room temperature electrons from the valence band can be LIFTED into the conduction band. The electrons can MOVE freely and act as charge carriers. ... A PURE undopedsemiconductor is known as intrinsicsemiconductor. | |
| 8. |
What is the value of solar constant? |
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Answer» ue of the CONSTANT is approximately 1.366kilowatts per square metre. The “constant” is FAIRLY constant, INCREASING by only 0.2 PERCENT at the peak of each 11-year SOLAR cycle. |
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| 10. |
What will you prefer - sofg iron oe steel , tl make an electromagnet ? Give reasons. |
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| 11. |
Caluclate the gravitational force due to the earth on mahendra in the earlier example. |
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Answer» wer for your question is if,MAHENDRA CAR WEIGHS 1000kgthe ANSWER will be F = 980 NPLEASE MARK AS BRAINLIEST |
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| 12. |
Is charge scalar or vector give explanation |
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Answer» is SCALAR quantity becausecharge doesn't have DIRECTION and scalar has only MAGNITUDE is REQUIRED to discribe it |
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| 13. |
What force will change the velocity of a bidy of mass 1kg from 20m/s to 30m/s in two seconds |
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| 14. |
What is the magnification of the mirror |
| Answer» CATION is the RATIO of HEIGHT of the IMAGE to the height of OBJECT | |
| 15. |
Give reason fossil fuel on burning create air pollution |
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Answer» ustrialized nations like the United States, modern life is unthinkable without fossil fuels. By most estimates, coal, OIL and natural gas are enough to supply 85 percent of America's energy demand. However, fossil fuel production also carries SEVERE economic, environmental and social costs. Much of the concern arises from the EMISSION of compounds like carbon dioxide, nitrogen oxides and sulfur dioxide into the atmosphere, resulting in potentially devastating long-term contamination of land, AIR and WATER resources.and hence causes air pollution |
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| 16. |
Real depth and apparent depth of a tank |
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Answer» to REFRACTION |
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| 17. |
Define the terms threshold frequency and stopping potential in the study of photoelectric emission. Explain briefly why the wave theory of light is unable to explain |
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Answer» avells about SOUND and there are some VALENCIA and do STOP it |
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| 18. |
For a single stage impulse turbine with a rotor diameter of 2m and a speed of 3000 rpm when nozzle angle is 20 degree, the optimum velocity of steam in m/s will be |
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Answer» raulic efficiency of an impulse TURBINE is MAXIMUM when velocity of wheel isIn a centrifugal pump, the water ENTERS the impeller __________ and leaves the vanes axially. A KAPLAN turbine is an AXIAL flow reaction turbine. The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is __________ of the jet velocity, A.hope it helps mark as brainlist |
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| 19. |
Speed of boat in stream water 15km/hr while speed of stream is 1.5km/hr what is the speed of boatman against stream |
| Answer» F BOAT WITHOUT the STREAM = 15-1.5=13.5speed of boat against the stream =13.5-1.5=12 | |
| 20. |
The velocity of electromagnetic waves in free space is 3×10 to the power of 8 m/s find the frequency of radio waves of wavelength 150 m |
| Answer» LIGHT SPEED in SPACE | |
| 21. |
How are sound waves called mechinacal Waves? answer in shory |
| Answer» AVES are called mechanical WAVES because they need a medium to TRAVEL through. Electromagnetic wavescan travel through space(without medium), whereas sound wavescannot. ... Sound waves are KNOWN asmechanical waves because they require a MATERIAL medium for their propagation. | |
| 22. |
A boy claps his hand and here’s the echo two seconds later if he is 480 m away from wall calculate the velocity of sound in air |
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Answer» - I think so I take it out by distance time speed RELATIONSHIPS and distance is DOUBLE BCOZ echo once GOES and then comes back |
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| 24. |
at what distance of plane mirror of focal length2.5m should a boy stand so that his image has height equal to half of original height |
| Answer» ACTUAL height be x=(x/2)/x=1/21/2= -v/uUsing sign CONVENTION, 1/2 = v/uu=2vThat is OBJECT distance is twice the image distanceSo, the object should be PLACED at the centre of curvature and the image will be FORMED at focus.Object should be placed at centre of curvature =2(2.5)=5cmThe image will be formed at focus =2.5cm | |
| 25. |
The particle executing SHM in a straight line has velocities 8 m/s p 7 m/s and 4 m/s at three points having distance 1 m from each other. what will be maximum velocity of particle ? |
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Answer» imum velocity of the particle will be √65 m/sExplanation : The maximum velocity of a particle executing SHM is GIVEN by,Vmax = AwThe velocity at any point X is given by,V² = w²(A²-x²)where w = angular velocity,A = amplitudex = distance from central positionlet the three points A,B,C are at a distance of d, d+1, d+2 meters from the central position,hence,V₁² = w²(A²-d²) = 64.............eq1V₂² = w²(A²-(d+1)²) = 49.............eq2V₃² = w²(A²-(d+2)²) = 16............eqn3subtracting eqn2 from eqn1 we get15 = w²(2d+1).................eqn4subtracting eqn3 from eqn2 we get33 = w²(2d+3)...........eqn5dividing eqn5 and eqn4 we get(2d+3)/(2d+1) = 33/15=> 30D + 45 = 66d + 33=> d = 1/3putting the value of d in eqn4 we get,15 = w²(2/3 + 1 )=> w = 3putting the value of w and d in eqn1 we getw²(A²-d²) = 64=> 9(A²-1/9) = 64=> A² = 64/9 + 1/9 = 65/9=> A = √65/3Hence maximum velocity of the particle,Vmax = Aw = √65 |
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| 26. |
Plzz help me in this question the atoms of copper contain electrons and the atoms of rubber also contain electrons?then why does copper conduct electricity but rubber does not conduct electricity?? |
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Answer» ny substance will be a conductor when it will have FREE electrons with witch it conducts electricity and heat. It is true that copper and RUBBER, both have electrons but copper has free electrons, which are RESPONSIBLE for flow of current and hence, conduct electricity but Rubber, on the other HAND, does not have free electrons and cannot conduct electricity and are CALLED insulators.That's the reason why rubber doesn't conducts electricity..Hope this will help u... :-) |
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| 27. |
What is SI unit of electrical conductance |
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Answer» mens (symbolized S) is the Standard INTERNATIONAL (SI) unit of electrical conductance. The archaic TERM for this unit is the mho (OHM spelled backwards). |
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| 29. |
Work done when you lift a object with mass m against the gravitational force |
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Answer» here m =MASS of OBJECT g=gravitational ACCELERATION H= HEIGHT of object . |
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| 30. |
Answer any 1 of them |
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Answer» 1111]... Hello User... [1001010101]Here's your answer...Q 36.c ICE = 2.1 J/g°CL FUSION = 336 J/gc water = 4.2 J/g°CL vaporisation = 2268 J/gHeat REQUIRED = 10×2.1×(0+5) + 10×336 + 10×4.2×100 + 10×2268= 105 + 3360 + 4200 + 22680= 30345 J[0110100101]... More questions detected...[010110011110]//Bot UnknownDude is moving on to more queries//This is your friendly NEIGHBOURHOOD UnknownDude |
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| 31. |
Pls help in solving this |
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Answer» a formula for this :h=ut^2After finding the TIME taken , substitute in the formula H=1/2at^2If you like my answer , pls PRESS the red HEART ❤️ . If it helps you , then don’t forget to MARK it as the brainliest answer . Thanks !#BeBrainly |
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| 33. |
The maximum magnification of a electron microscope is |
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Answer» scanning transmission electron MICROSCOPE has achieved better than 50 PM resolution in ANNULAR dark-field IMAGING mode and MAGNIFICATIONS of up to about 10,000,000x whereas most light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications below 2000x. |
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| 34. |
Describe the position of the source of light with respect to concave mirror torch light projector lamp and food light |
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Answer» ight _ focus Same for flood light BCOZ strong parallel RAYS will COME out of them only if light source is placed at focus of parabolic (concave ) mirror hope it helps!! |
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| 35. |
Any one can send the class 11 imp questions of physics |
| Answer» E....You can get it from google and ALSO from u tube.Hope it will HELP you. | |
| 36. |
in an experiment to study the dependence of current on potential difference across a resistor a student obtained the graph as shown in the diagram |
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Answer» s the RESISTANCE of the RESISTOR by the FORMULA |
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| 37. |
List all the forms of energy that you use in a day. Where do we get these different form of energy ?? |
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Answer» different FORM of ENERGY in our daily life . some of them are:1) Chemical energy - from foods2) LIGHT energy- from sun and electric bulb3) Heat energy- from sun 4) Hydro energy - from water 5) BIO -- mass energy- from plants and animals residuesI hope you will get.... |
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| 38. |
Arrange the alpha ,beta , and gamma in ascending order with to their charge. |
| Answer» AYS have no CHARGE.Beta RAYS have NEGATIVE charge.Alpha rays have POSITIVE charge. | |
| 39. |
Define the weight of a body. Also mention its S.I unit |
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Answer» of a BODY is the force by which earth or any other CELESTIAL body pulls it . It's SI UNIT is NEWTON. |
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| 40. |
If the work done by force in moving an object through a distance of 20 cm is 24.2 Joule, what is the magnitude of the force |
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Answer» e =W FORCE =F DISPLACEMENT =S Given,W = 24.2 jS = 20cm=0.2m W= F×S 24.2 =F×0.2 F=24.2/0.2 hence, F = 121 NEWTON or N |
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| 41. |
The height at which the weight of a body becomes 1/9th its weight on the surface of earth |
| Answer» SURFACE of EARTH the WEIGHT of BODY will be 4.5 | |
| 42. |
A stone of mass M Falls from the top of a tower of height H and it is itself a distance H/8 deep in sand. The time of its penetration in sand is Options :- 1)Under root h/32g 2)Under root root h/8g 3) 1/2 × Under root h/2g 4)None of these |
| Answer» WER will be 2 | |
| 43. |
Reflection of transverse and longitudinal wave from denser to rarer mefium |
| Answer» GHT ENTERS from rare to DENSER medium. light bends toward the NORMAL | |
| 44. |
is angle of incident increases angle of deviation decreases but after certain value of angle of incidence the angle of deviation increases what that what is that specific value of angle of incident called does this angle same for all for light of all colours |
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Answer» is just an DEVICE or an instrument where the IMAGE formed is to be observed. If the SCREEN is removed, the lens will continue to form the image on its focus. Thus, on removing the screen and on looking through the lens in the direction of the object the image of the distant TREE is inverted and formed at the focus . |
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| 45. |
The specific heat of Argon at constant volume is 0.3122k.J/kg/K. Find the specific heat ofArgon at constant pressure if R=8.314 kJ/kmole K. (Molecular weight of argon =39.95)1) 5203 2) 53023) 2305. 4)3025 |
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Answer» ungsten not argonOk |
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| 46. |
What type of image is formed in a selfie ? |
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Answer» nvex MIRROR so it GIVES a REAL and DIMINISHED IMAGE |
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| 47. |
A bird is flying at the height 3 m above the river surface while a fish is 4 m below the surface. At what depth would the fish appear to the bird ? At what height the bird would appear to fish ? |
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Answer» The correct answers are 8 m and 7 m.Explanation:The expression for the refractive index in terms of apparent DEPTH in air is as follows;Put and REAL depth in air= 3 m.The FISH would see the bird at 4+4 = 8 m.The bird would see the fish at 3 m + 4 m= 7 m.Therefore, the fish would appear to the bird at depth of 8 m. The bird would appear to fish at the HEIGHT of 7 m. |
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| 48. |
Draw diagrams to detect the behaviour of magnetic field lines when a diamagnetic and paramagnetic material is |
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| 49. |
If two objects of different weight are dropped indigo which falls faster |
| Answer» OU NAME it and we will FIND | |