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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.
| 5101. |
What is the significance of precision ? |
| Answer» | |
| 5102. |
Which is the most accurate clock ? |
| Answer» NiST-F1 (\xa0a cesium fountain clock), | |
| 5103. |
Differentiated/dx(x3.sin4x)\xa0 |
| Answer» Use chain rule for it,{tex}{d\\over dx}(x^3.sin4x){/tex}{tex}= x^3.{d\\over dx}(sin 4x) + sin4x. {d\\over dx} (x^3){/tex}{tex}= x^3.cos4x.{d\\over dx}(4x) + sin4x.3x^2{/tex}{tex}= 4x^3cos4x + 3x^2sin4x{/tex} | |
| 5104. |
\xa0how spectograph work?\xa0 |
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| 5105. |
Define gravition. |
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| 5106. |
Why we take force are equal when we connect two springs in series ? |
| Answer» | |
| 5107. |
Will the momentum remain constant if some external force acts on the system? |
| Answer» Ans. If an external force is acted on a body to move it, the body accelerates. So the momentum cannot be a constant.But, if the force cannot make a body to move like push of a boy on a wall, The body remains at rest and the momentum of the body remains zero. | |
| 5108. |
Variation of acceleration due to gravity due to rotation of earth |
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| 5109. |
Which point on the curve corresponds to elastic limit and yield point of the wire? |
| Answer» | |
| 5110. |
What is rolling motion |
| Answer» Rolling is a type of motion that combines rotation (commonly, of an axially symmetric object) and translation of that object with respect to a surface (either one or the other moves), such that, if ideal conditions exist, the two are in contact with each other without sliding. | |
| 5111. |
Can water be bolied without boiling?\xa0 |
| Answer» | |
| 5112. |
What is the room temperature to be used in solving physics numerical\xa0\xa0 |
| Answer» 25C | |
| 5113. |
What is kinetic friction , static friction and limiting friction |
| Answer» Ans.\xa0\tStatic friction acts because the body tends to move when a force is applied on it.\tLimiting friction\xa0is the\xa0friction\xa0on a body just before it starts moving. Generally,limiting friction\xa0is highest.\xa0\tKinetic friction\xa0is the\xa0friction\xa0which acts on the body when the body is moving. | |
| 5114. |
When should we take sine or cosine functions to represent a SHM? |
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| 5115. |
why a black body emits radiation just after aborbing radiation. |
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| 5116. |
write the relation between two angles for hich horizontal ranges will be equal. |
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Answer» Ans.\xa0Let\xa0two\xa0angles\xa0of\xa0projection\xa0for\xa0which\xa0the\xa0horizontal\xa0range\xa0is\xa0same\xa0are\xa0α\xa0and\xa0β.Then\xa0the\xa0relation\xa0b/w\xa0them\xa0:\xa0α\xa0+\xa0β\xa0=\xa090° \xa0Let\xa0two\xa0angles\xa0of\xa0projection\xa0for\xa0which\xa0the\xa0horizontal\xa0range\xa0is\xa0same\xa0are\xa0α\xa0and\xa0β.Then\xa0the\xa0relation\xa0b/w\xa0them\xa0:α+β\xa0=\xa090°\xa0 |
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| 5117. |
Position of an object at a particular time-diplacement or distance?\xa0 |
| Answer» And. It\'s displacement | |
| 5118. |
When is the initial velocity taken negative\xa0 |
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Answer» if I started from A and go\xa0to B in a direction and then returned back to A and go in a direction opposite to N then my velocity is -ve with respect to N. A vector points in a direction in space. A negative vector (or more precisely "the negative of a vector") simply points the opposite way.If I drive\xa0from\xa0my home\xa0to\xa0my workplace (and then defining my\xa0positive direction\xa0in that way), then my velocity is\xa0positive if I go to work, but\xa0negative when I go homefrom work. It is all about direction seen from how I defined my positive\xa0axis. |
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| 5119. |
What is the reason behind frictional force between layers of fluids? |
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Answer» Ans. It is due to the internal frictional force that develops between different layers of fluids as they are forced to move relative to each other. The reason behind frictional force between layers of fluids:i) intermolecular force of cohesion(ii) molecular momentum exchange |
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| 5120. |
What is the difference between stress and strain? |
| Answer» \tStress is defined as a force that can cause a change in an object or a physical body while strain is the change in the form or shape of the object or physical body on which stress is applied.\tStress can occur without strain, but strain cannot occur with the absence of stress.\tStress can be measured and has a\xa0unit\xa0of measure while strain does not have any unit and, therefore, cannot be measured.\tStrain is an object’s response to stress while stress is the force that can cause strain in an object | |
| 5121. |
Effect of combination of two waves of same frequency travelling ino opposite direction |
| Answer» Two waves (with the same amplitude, frequency, and wavelength) are travelling in opposite directions. Using the principle of superposition, the resulting wave amplitude may be written as:y\xa0(\xa0x\xa0,\xa0t\xa0)\xa0=\xa0y\xa0m\xa0sin\xa0(\xa0kx\xa0-\xa0ωt\xa0)\xa0+\xa0y\xa0m\xa0sin\xa0(\xa0kx\xa0+\xa0ωt\xa0)\xa0=\xa02\xa0y\xa0m\xa0sin\xa0(\xa0kx\xa0)\xa0cos\xa0(\xa0ωt\xa0)This wave is no longer a travelling wave because the position and time dependence have been separated. The the wave amplitude as a function of position is\xa02ymsin(kx). This amplitude does not travel, but stands still and oscillates up and down according to cos(ω t). Characteristic of standing waves are locations with maximum displacement (antinodes) and locations with zero displacement (nodes)..If two sinusoidal waves having the same frequency (and wavelength) and the same amplitude are travelling in opposite directions in the same medium then, using superposition, the net displacement of the medium is the sum of the two waves.when the two waves are 180° out-of-phase with each other they cancel, and when they are exactly in-phase with each other they add together. As the two waves pass through each other, the net result alternates between zero and some maximum amplitude. However, this pattern simply oscillates; it does not travel to the right or the left, and thus it is called a "standing wave". | |
| 5122. |
does centre of mass of any body lie outside the body |
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Answer» Very crudely,\xa0centre of mass\xa0is the point where the\xa0mass\xa0appears to be concentrated. In a non-uniform gravitational field, it doesn\'t coincide with\xa0centre of mass. It\xa0can\xa0also\xa0lie outside the body. Since torque\xa0can\xa0be measured around\xa0any\xa0axis, it is not necessary for the\xa0centre of gravity\xa0to\xa0lie\xa0inside the\xa0body. Centre of mass is hypothetical geometry point where whole mass of body is concentrated. It is position vector.Centre of mass may lie outside the body. |
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| 5123. |
When the sum of the two vectors maximum and when minimum\xa0 |
| Answer» Two vectors will be maximum when angle between them is 0 degreeTwo vectors will be minimum when angle between them is 180 degree | |
| 5124. |
An athelete runs a certain distance before taking a long jump. Why ? |
| Answer» An athlete always runs for some distance before taking a jump so that inertia of motion may help him in his muscular efferts to take a longer jump. | |
| 5125. |
Why gravitation force is considerd to be conservative?? |
| Answer» Gravitational forece is called as conservative force because it acts equally to all objectes irrespective of thier mass and size if placed at equal distance. | |
| 5126. |
what is path length? |
| Answer» Path lenght is the total distance travelled by an object from the starting point regardless of where it travelled .In physics, there are two definitions for "path length." The first is defined as the total distance an object travels. Unlike displacement, which is the total distance an object travels from a starting point, path length is the total distance travelled, regardless of where it travelled. The second is synonymous with wavelength and is used in calculating constructive and destructive interference of waves. | |
| 5127. |
which will carry more load-a single coir or a combination of coirs?\xa0 |
| Answer» A bunch of wire is more flexible than a single one so it will carry more load | |
| 5128. |
which will carry more load- |
| Answer» A combination of core will carry more load | |
| 5129. |
Bring out six differences between linear and rotational motion\xa0 |
| Answer» Linear motion :- A type of motion in which particle moves in straight line. It follows all linear kinematic equations like v = u + at, S = ut + 1/2at² , v² = u² + 2aS etc.Example :- motion of bikes, walking man, running athletic etc are example of linear motion.Rotational motion :- A motion of rigid body which takes place in such a way that all particles of its moves in a circle about an axis with a common angular velocity.Example :- motion of stone, rotation of earth, planets are the example of rotational motion. It follows both linear as well as angular equations. angular equations like ω = ω₀ + αt etc | |
| 5130. |
ratio of space average velocity and time average velocity explain |
| Answer» You can get your doubts cleared instantly, 24/7 with IIT/AIIMS tutors on HashLearn. Download here: http://bit.ly/2fDYZtb | |
| 5131. |
Relation between alpha and gama? |
| Answer» You can get your doubts cleared instantly, 24/7 with IIT/AIIMS tutors on HashLearn. Download here: http://bit.ly/2fDYZtb | |
| 5132. |
All constants are dimensionless. Comment |
| Answer» not necessary that all constant are dimensionless.for some constant have it has dimension and some dont havefor eg:gravitational constant ,g,planck\'s constant etc have dimension\xa0 | |
| 5133. |
why steel is more elastic than rubber? |
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Answer» upper vale ne galat answer deya hai \xa0To quantify elasticity, physics defines elasticity as "resistance to change". The greater the resistance to change, the greater is the elasticity of the material and the faster it comes back to its original shape or configuration when the deforming force is removed. By this definition, steel is more elastic than rubber because steel comes back to its original shape faster than rubber when the deforming forces are removed. |
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| 5134. |
Bernaullis theorem derivation\xa0 |
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Answer» Ans\xa0.\xa0Proof\xa0:\xa0Let\xa0the\xa0velocity,\xa0pressure\xa0and\xa0area\xa0of\xa0a\xa0fluid\xa0column\xa0at\xa0a\xa0point\xa0X\xa0be\xa0v1,\xa0p1and\xa0A1\xa0and\xa0at\xa0another\xa0point\xa0Y\xa0be\xa0v2,\xa0p2\xa0and\xa0A2.\xa0Let\xa0the\xa0volume\xa0that\xa0is\xa0bounded\xa0by\xa0X\xa0and\xa0Y\xa0be\xa0moved\xa0to\xa0M\xa0and\xa0N.\xa0let\xa0XM\xa0=\xa0L1\xa0and\xa0YN\xa0=\xa0L2.\xa0Now\xa0if\xa0we\xa0can\xa0compress\xa0the\xa0fluid\xa0then\xa0we\xa0have,\xa0\xa0A1\xa0×\xa0L1=\xa0A2\xa0×\xa0L2We\xa0know\xa0that\xa0that\xa0the\xa0work\xa0done\xa0by\xa0the\xa0pressure\xa0difference\xa0per\xa0volume\xa0of\xa0the\xa0unit\xa0is\xa0equal\xa0to\xa0the\xa0sum\xa0of\xa0the\xa0gain\xa0in\xa0kinetic\xa0energy\xa0and\xa0gain\xa0in\xa0potential\xa0energy\xa0per\xa0volume\xa0of\xa0the\xa0unit.This\xa0implies\xa0Work\xa0done\xa0=\xa0force\xa0×\xa0distance\xa0⇒\xa0Work\xa0done\xa0=\xa0\xa0p\xa0×\xa0volumeTherefore,\xa0net\xa0work\xa0done\xa0per\xa0volume\xa0=\xa0p1\xa0–\xa0p2\xa0\xa0Also,\xa0kinetic\xa0energy\xa0per\xa0unit\xa0volume\xa0=\xa012\xa0mv2\xa0=\xa012\xa0ρv2Therefore,\xa0we\xa0have,Kinetic\xa0energy\xa0gained\xa0per\xa0volume\xa0of\xa0unit\xa0=\xa012\xa0ρv22\xa0-\xa0v12And\xa0potential\xa0energy\xa0gained\xa0per\xa0volume\xa0of\xa0unit\xa0=\xa0pg\xa0(h2\xa0–\xa0h1)Here,\xa0h1\xa0and\xa0h2\xa0are\xa0heights\xa0of\xa0X\xa0and\xa0Y\xa0above\xa0the\xa0reference\xa0level\xa0taken\xa0in\xa0common.Finally\xa0we\xa0have\xa0\xa0p1\xa0–\xa0p2\xa0=\xa012ρ\xa0v22-v12\xa0+\xa0ρg\xa0(h2\xa0–\xa0h1)⇒\xa0\xa0p1\xa0+\xa012\xa0ρ(v1)2\xa0+\xa0ρgh1\xa0=\xa0p2\xa0+\xa012ρ\xa0(v2)2\xa0+\xa0ρgh2⇒\xa0\xa0p\xa0+\xa012ρv2\xa0+\xa0ρgh\xa0is\xa0a\xa0constant\xa0\xa0When\xa0we\xa0have\xa0h1\xa0=\xa0h2\xa0\xa0Then\xa0we\xa0have,\xa0p\xa0+\xa012\xa0ρv2is\xa0a\xa0constant.\xa0\xa0This\xa0proves\xa0the\xa0Bernoulli’s\xa0Theorem Ans.\xa0According\xa0to\xa0Bernoulli’s\xa0theorem\xa0in\xa0physics,\xa0whenever\xa0there\xa0is\xa0an\xa0increase\xa0in\xa0the\xa0speed\xa0of\xa0the\xa0liquid,\xa0there\xa0is\xa0a\xa0simultaneous\xa0decrease\xa0in\xa0the\xa0potential\xa0energy\xa0of\xa0the\xa0fluid\xa0or\xa0we\xa0can\xa0say\xa0that\xa0there\xa0is\xa0a\xa0decrease\xa0in\xa0the\xa0pressure\xa0of\xa0the\xa0fluid.\xa0Basically,\xa0it\xa0is\xa0a\xa0principle\xa0of\xa0conservation\xa0of\xa0energy\xa0in\xa0the\xa0case\xa0of\xa0ideal\xa0fluids.\xa0If\xa0the\xa0fluid\xa0flows\xa0horizontally\xa0such\xa0that\xa0there\xa0is\xa0no\xa0change\xa0in\xa0the\xa0gravitational\xa0potential\xa0energy\xa0of\xa0the\xa0fluid\xa0then\xa0increase\xa0in\xa0velocity\xa0of\xa0the\xa0fluid\xa0results\xa0in\xa0a\xa0decrease\xa0in\xa0pressure\xa0of\xa0the\xa0fluid\xa0and\xa0vice\xa0versa. |
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| 5135. |
Show that no work is done by Lorentz force on charged particle ? |
| Answer» Ans.\xa0Lorentz Force is given by\xa0F→\xa0=\xa0qv→×B→as the force is always perpendicular to the motion and work done given by\xa0W\xa0=\xa0F.S\xa0cosθ, as angle is always 90 so work done will be Zero.\xa0 | |
| 5136. |
What is viscosity?\xa0 |
| Answer» Ans. Viscosity\xa0is an internal property of a fluid that offers resistance to flow. | |
| 5137. |
Derive kinetic energy by calculus method\xa0 |
| Answer» Ans.\xa0When there are no opposing forces, a moving body tends to keep moving with a steady velocity as we know from Newton\'s first law of motion. If, however, a resultant force does act on a moving body in the direction of its motion, then it will accelerate per Newton\'s second law\xa0F\xa0=\xa0ma\xa0The work done by the force will become converted into increased kinetic energy in the body.\xa0Derivation Using Calculus\xa0:Begin with the Work-Energy Theorem :\xa0The work that is done on an object is related to the change in its kinetic energy\xa0∆K\xa0=\xa0WRewrite work as an integral:\xa0we can represent the work done\xa0in terms of a velocity differential.∆K\xa0=\xa0∫F.\xa0drRewrite force in terms of velocity:\xa0mass is a scalar and can therefore be factored out.\xa0∆K\xa0=\xa0∫ma.dr=>\xa0∆K\xa0=\xa0m∫a.dr=>\xa0∆K\xa0=\xa0m∫dvdt.dr=>\xa0∆K\xa0=\xa0m∫drdt.dv=>\xa0∆K\xa0=\xa0m∫v.dv=>\xa0∆K\xa0=\xa012mv2\xa0\xa0 | |
| 5138. |
Can use a pendulum watch an artificial satelite? |
| Answer» An artificial satellite constitutes a freely falling body.Hence,the effective gravity inside a satellite is zero.If g=0,its time period becomes infinite .that\'s why pendulum will not oscillate .In other words, it will oscillate with a time period. | |
| 5139. |
I need Derivation on Carnot Cycle From Thermodynamics |
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| Answer» For this questions you will need some mathematics and knowledge of engineering thermodynamics. Appropriate links are provided at the bottom of this section. As we saw previously all Carnot heat engine have the same efficiency irrespective of the working gas we are using. Hence, we might as well use an\xa0ideal gas\xa0with\xa0temperature-independent specific heats\xa0because its properties are precisely known and can be represented in terms of fairly easy equations. All noble gases ( helium, neon, argon, krypton, xenon, and the radioactive radon ) come extremely close to being an ideal gas at temperatures and pressure relevant to Stirling engine.(6) p V = m Rs\xa0T Ideal gas law(7) Δu = cv\xa0ΔT Change of internal energy is proportional to change in temperature\t | Figure 5 : Carnot Cycle | 1 → 2 : isothermal compression. Because temperature is constant the internal energy of the gas does not change according to Eq.(2). According to Eq.(1) we also have\xa0p\xa0V\xa0=\xa0m\xa0R\xa0Tc=\xa0constant. This makes it possible to evaluate the work integral Wc\xa0=∫\xa0p\xa0dV This results in the equation : (8) Qc=Wc\xa0= m Rs\xa0Tc\xa0ln ( V1 / V2 )3 → 4 : isothermal expansion. This follows exactly the logic as the process 1 → 2. Hence, (9) Qh=Wh\xa0= m Rs\xa0Th\xa0ln ( V4 / V3 )2 → 3 : adiabatic compression. With κ = cp/cv\xa0for such process : (10) V2/V3\xa0= (Th/Tc)1/(κ-1)4 → 1 : adiabatic expansion. Follows the same logic as process 2 → 3 with the result: (11) V1/V4\xa0= (Th/Tc)1/(κ-1)\tWe use Eq.(8) and (9) to find a first expression for the efficiency of the Carnot cycle (see also Eq.(3) ) :(12) η = 1 - Qc/Qh\xa0= 1 - (Tc\xa0ln ( V1 / V2 )) / (Th\xa0ln ( V4 / V3 ))From Eq. (10) and (11) we get :(13) V1/V2\xa0= V4/V3and therefore :(14) η = 1 - Tc/Thi hope that you will like it|
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| 5140. |
Brownian motion is observable since Avogadro number is infinite,, comment. |
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| 5142. |
Calculate the value of G in British system |
| Answer» | |
| 5143. |
write down the zeroth and first law of thermodynomics? |
| Answer» Ans.\xa0The Zeroth Law of Thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other.The first law, also known as Law of Conservation of Energy\xa0states that energy cannot be created or destroyed in an isolated system. | |
| 5144. |
What is triple point water |
| Answer» Ans. The particular temperature and pressure at which the solid, liquid, and gaseous phases of a given substance are all at equilibrium with one another is known as Triple Point Water. | |
| 5145. |
What is relation between linear expansion or superficial expansion |
| Answer» Ans.\xa0The amount by which unit length of a material increases when the temperature is raised by one degree is called the coefficient of linear expansion and is represented by \\(\\alpha\\)\xa0(Greek alpha).The amount by which unit area of a material increases when the temperature is raised by one degree is called the coefficient of superficial (i.e. area) expansion and\xa0represented by \\(\\beta\\)(Greek beta).Relation b/w both :\xa0\\(\\beta = 2 \\alpha\\) | |
| 5146. |
What is the distance between a node and the nearest antinode ? |
| Answer» Ans.\xa0A node is a place of zero amplitude. An antinode is a place of maximum amplitude.The distance between successive nodes, and successive antinodes, is half a wavelength.\xa0\\(({\\lambda \\over 2})\\) | |
| 5147. |
What is difference between stress and strain ??? |
| Answer» Stress is same as that of PRESSURE which is force per unit area and thus have dimensions M1L-1T-2 same as that of PRESSURE.\xa0While STRAIN means the ratio of change in dimension and original dimension. Thus it is a dimension less quantity.\xa0 | |
| 5148. |
Derive newton\'s formula for velocity of sound in air |
Answer» According to Newton, when sound waves propagate in air, compression\xa0and\xa0rarefaction\xa0are formed. He assumed that the process is very slow and the heat produced during compression is given to surrounding and heat loss during compression is gained from surrounding. So the temperature remains constant and sound waves propagate through an isothermal process.According to gas law (Boyle\'s law),PV = constantwhere, P = pressure V = volume of airDifferentiating above equation, we getwhere,\xa0B\xa0is the bulk modulus of the air.If\xa0B\xa0is the bulk modulus of the air,\xa0v\xa0is velocity and\xa0ρ\xa0is the density, then, velocity is given by:This is the required expression for velocity of sound in air. |
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| 5150. |
First law of thermodynamic\xa0 |
| Answer» The\xa0first law of\xa0thermodynamics\xa0is a version of the law of\xa0conservation of energy which states that the total\xa0energy\xa0of an\xa0isolated system\xa0is constant i.e. energy can be transformed from one form to another but cannot be created or destroyed. The first law is often formulated by stating that the change in the\xa0internal energy\xa0of a\xa0closed system\xa0is equal to the amount of\xa0heat\xa0supplied to the system plus\xa0the amount of\xa0work\xa0done by the system on its surroundings.\xa0 | |
