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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.
| 9601. |
Why we can difine the direction of work? |
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Answer» As it is a scalar quantity....so it doesn\'t have direction..... ??priya good definition so we get W = F multiplied by s multiplied by COS.when something is multiplied by cos then it is known as a scalar quantity and a scalar quantity has only magnitude and no direction.SO WORK IS A SCALAR QUANTITY AND WORK DOES NOT HAVE ITS OWN DIRECTION.THE DIRECTION OF WORK IS THE DIRECTION OF FORCE AND DISPLACEMENT SorryWhy we can not define the direction of work done? |
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| 9602. |
Procedure of screw guage experiment |
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| 9603. |
Explain the phenomenon of rounding a level road |
| Answer» To manage the balance of body through cetrifugal force | |
| 9604. |
How the internal energy of an ideal gas and real gas differ from each other? |
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Answer» In ideal gas internal energy depends only on temperature of gas because the intermolecule bond does not exist in ideal gas. But in real gas internal energy is sum of potential and kinetic energy. Kinetic energy depends on intermolecule bonds and kinetic energy depends on temperature. This will help u Google will help u |
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| 9605. |
In which condition force can be negative |
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Answer» Thanks Opposite direction Force is negative when it is applied to opposite direction . |
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| 9606. |
Question paper or last year post mid term |
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| 9607. |
G Night Everyone????????????????? |
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| 9608. |
Which students are study DAV School ,CBSE Aflliated |
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| 9609. |
a stone breaks tbe wi dow oane into pieces while a bullet perces through the same. give reason |
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| 9610. |
Work done in isothermal process |
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| 9611. |
HIMATIA7U enter it in my cbse wallet and get 50 rupeesPlease any one give me your code |
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| 9612. |
Hi..... Every one |
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| 9613. |
how to calculate torque in vector form |
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Answer» 1.torque=r×f sin theta2.torque= moment of inertia(l)×angular accelation(a) Priya correct your formula please Sorry its T-r. F where T-torque, r-perpendicular distance , F - force T- l . Alpha T=I×alpha T=r×F |
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| 9614. |
Keplar third laws |
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Answer» ?? Ohh yes!!!what i was looking for!!!? Third law of Kepler. The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. This captures the relationship between the distance of planets from the Sun, and their orbital periods. Mathematically......T^2=(a)^3.....i don\'t know it\'s significance ??? |
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| 9615. |
Relation between alpha beta and gamma |
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Answer» Relation between alpha, beeta and gamma alpha : beeta : gamma =1: 2: 3 Alpha = beta/2 = gamma/3 |
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| 9616. |
Fourth equation of motion |
| Answer» Circular motion | |
| 9617. |
Derivation of Newtons law of cooling. |
| Answer» Newton\'s Law of Cooling states that the temperature of a body changes at a rate proportional to the difference in temperature between its own temperature and the temperature of its surroundings. We can therefore writedTdt=−k(T−Ts)dTdt=−k(T−Ts)where,T = temperature of the body at any time, tTs = temperature of the surroundings (also called ambient temperature)To = initial temperature of the bodyk = constant of proportionality dTdt=−k(T−Ts)dTdt=−k(T−Ts)dTT−Ts=−kdtdTT−Ts=−kdtln(T−Ts)=−kt+lnCln\u2061(T−Ts)=−kt+ln\u2061Cln(T−Ts)=lne−kt+lnCln\u2061(T−Ts)=ln\u2061e−kt+ln\u2061Cln(T−To)=lnCe−ktln\u2061(T−To)=ln\u2061Ce−ktT−Ts=Ce−ktT−Ts=Ce−kt when t = 0, T = ToC=To−TsC=To−Ts Thus,T−Ts=(To−Ts)e−ktT−Ts=(To−Ts)e−ktT=Ts+(To−Ts)e−ktT=Ts+(To−Ts)e−ktThe formula above need not be memorized, it is more useful if you understand how we arrive to the formula. | |
| 9618. |
Derive the expression for the work done by a torque |
| Answer» Given our definition of work as\xa0W\xa0=\xa0Fs\xa0, can we generate an expression for work done on a rotational system? To derive our expression we begin by taking the simplest case: when the force applied to a particle in rotational motion is perpendicular to the radius of the particle. In this orientation, the force applied is parallel to the displacement of the particle, and would exert the maximum work. Given this situation the work done is simply\xa0W\xa0=\xa0Fs\xa0, where\xa0s\xa0is the arc length that the force acts through in a given period of time. Recall, however, that arc length can also be expressed in terms of the angle swept out by the arc:\xa0s\xa0=\xa0rμ\xa0. Our expression for work in this simple case becomes:W\xa0=\xa0Frθ\xa0=\xa0τμ Since\xa0Fr\xa0gives us our torque, we can simplify our expression in terms of only\xa0τ\xa0and\xa0μ\xa0.What if the force is not perpendicular to the radius of the particle? Let the angle between the force vector and the radius vector be\xa0θ\xa0, as shown below.Figure %: A force acting at angle\xa0θ\xa0to the radius of rotation of point PTo compute the work we calculate the component of the force acting in the direction of the particle\'s displacement. In this case, this quantity is simply\xa0F\xa0sinθ\xa0. Again, this force acts over an arc length given by\xa0rμ\xa0. Thus the work is given by:W\xa0= (F\xa0sinθ)(rμ) = (Fr\xa0sinθ)μRecall thatτ\xa0=\xa0Fr\xa0sinθThus\xa0W\xa0=\xa0τμ\xa0Surprisingly enough, this equation is exactly the same as our special case when the force acted perpendicular to the radius! In any case, the work done by a given force is equal to the torque it exerts multiplied by the angular displacement.For you calculus types, there is also an equation for work done by variable torques. Instead of deriving it, we can just state it, as it is quite similar to the equation in the linear case:W\xa0= τdμ Thus we have quickly gone through deriving our expression for work. The next thing after work we studied in linear motion was kinetic energy, and it is to this topic that we turn.Rotational Kinetic EnergyConsider a wheel spinning in place. Clearly the wheel is moving, and has a kinetic energy attached to it. But the wheel is not engaged in translational motion. How do we calculate the kinetic energy of the wheel? Our answer is similar to how we calculated the result of a net torque on a body: by summing over each particle. | |
| 9619. |
Find the centre of mass of a triangular lamina? |
| Answer» Let the lamina (\xa0ΔLMN) is subdivided into narrow strips each parallel to the base (MN)By symmetry, each and every strip has its centre of mass at its mid-point.On joining the mid-points of all strips we get the median LP. Therefore the centre of mass of the triangle as a whole lie on the median LP. Similarly, we can say that it lies on the median MQ and NR. It means that centre of mass lies on the point of concurrence of the median, which is on the centroid G of the triangle. | |
| 9620. |
Derivation of alpha beta and gamma |
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| 9621. |
What is triple point of water ? |
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Answer» Thanks Triple point is the intersection on a phase diagram where three phases coexist in equilibrium. Triple point of water is the stage where solid liquid and vapour all exists.The triple point of water, 273.16 K ( 00C) at a pressure of 611.2 Pa |
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| 9622. |
Laws of photoelectric effect |
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| 9623. |
Laws of photoelectric current |
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| 9624. |
What is different between thermal capacity and water equivalent? Explain me. |
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Answer» Ok No |
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| 9625. |
What is the difference between gravity and gravatation |
| Answer» Gravitation is the attractive force existing between any two objects that have mass. The force of gravitation pulls objects together. Gravity is the gravitational force that occurs between the earth and other bodies. Gravity is the force acting to pull objects toward the earth. | |
| 9626. |
Is there any change in the cbse syllabus for the next year |
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Answer» U are right yakshi Have u forgot????we have already talked about it before.....??? |
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| 9627. |
Example 11.7 ncert |
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| 9628. |
Derive the expression for modulus of elasticity |
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Answer» hook\'s lawstress is directly proportional to strain, then stress equal to EstrainThen E=stress/strain Stress/strain |
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| 9629. |
Find the expression for velocity of particle in simple harmonic motion |
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| 9630. |
Explain Bernoullies\' theorem? |
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Answer» It states that if the volume decreasea pressure increases . volume is inversely praportional to pressure Bernoulli\'s principle states that an increase in the velocity(v) of a fluid occurs simultaneously with a decrease in pressure(p) or a decrease in the fluid’s potential energy(gz) (where g=acceleration due to gravity,(z)or(h)=height ”.“Bernoulli\'s principle states that as a fluid moves around an object it creates different pressures on that object”.When the velocity of fluid is more the pressure tends to be less and the vice versa as we know pressure and velocity are inversely proportional. |
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| 9631. |
Show that surface energy is numerically equal to the surface tension. |
| Answer» Surface tension of the liquid=Force/lengthmultiply length to both numerator and the denominator=Force x length/length x length =work/area So, this\xa0show that the surface energy per unit area is equal to the surface tension of the liquid. | |
| 9632. |
What happens to time period of Earth if its volume reduce 1/27? |
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| 9633. |
What is the angle between the vector AxB and BxA |
| Answer» Since they\'re in opposite directions, the angle between them is 180 degrees. 180° or 0° depending on how you\'d like to define the angle between two vectors. Because a×b=-b×a, the two vectors are anti-parallel, both along the same axis but pointing in opposite directions. The other answers are correct in saying that… | |
| 9634. |
Iskdbdbnd |
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Answer» What is this?? ???? What is this What\'s this????? R u alright???????? ?? |
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| 9635. |
If 4m is the speed and total time is 5s then distance is |
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Answer» 20 m Yes....it will be 20 because there is not any extra condition If 4 m/s is the speed and time is 5s then distance is 20 m. 20 |
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| 9636. |
Derive the bernoleg theorem |
| Answer» It is Bernoulli\'s Theorem, RIGHT!!!!theorem noun Definition of Bernoulli\'s theorem 1 [ after Jacques Bernoulli ] : a basic principle of statistics: as the number of independent trials of an event of theoretical probability p is indefinitely increased, the observed ratio of actual occurrences of the event to total trials approaches p as a limit .2. [ after Daniel Bernoulli ] : a law of hydrodynamics: in a stream of liquid the sum of the elevation head, the pressure head, and the velocity head remains constant along any line of flow provided no work is done by or upon the liquid in the course of its flow and decreases in proportion to the energy lost in viscous flow | |
| 9637. |
Derive center of mass |
| Answer» Center of Mass refers to a point where whole body’s mass is concentrated.If there are two masses (m1, m2) separated by distances x1 and x2 from a fixed point. The Center of Mass (X) is expressed byX=m1x1 +m2x2/ m1+m2If there are n number of masses (m1, m2,..mn) having distances x1, x2,……xn then the Center of mass (X) is expressed by X =m1x1+m2x2+.................mnxn/ m1+m2+...mn | |
| 9638. |
Show that angle of repose is equal to the of friction |
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| 9639. |
Whaat is venturimetet |
| Answer» A venturimeter is a device used to measure the fluid flow through pipes. This flow measurement device is based on the principle of Bernoulli’s equation. Inside the pipe , pressure difference is created by reducing the cross-sectional area of the flow passage | |
| 9640. |
haaa bolo nancy or priya |
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| 9641. |
What is mechenical equivalent of heat ?? |
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Answer» Your wellcome Ok And for you knowledge -The mechanical equivalent of heat was a concept that had an important part in the development and acceptance of the conservation of energy and the establishment of the science of thermodynamics in the 19th century. Again thanks ayushi In the history of science, the mechanical equivalent of heat states that motion and heat are mutually interchangeable and that in every case, a given amount of work would generate the same amount of heat, provided the work done is totally converted to heat energy. |
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| 9642. |
What is projectile motion? Find equation for time of flight, range |
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| 9643. |
Relation between acceleration due to gravity and gravitational constant |
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Answer» The acceleration due to gravity depends on the mass of the body, the distance from the center of mass, and a constant G, which is called the "universal gravitational constant". Its value is = 6.673 x 10-11 N. m2/kg2.g=GM/ r^2 Acceleration due to gravity is 9.8 m/s2. |
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| 9644. |
What is differwnce between slope and gradient |
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Answer» A gradient is a vector, and slope is a scalar. Gradients really become meaningful in multivarible functions, where the gradient is a vector of partial derivatives. With single variable functions, the gradient is a one dimensional vector with the slope as its single coordinate (so, not very different to the slope at all). The degree of inclination or the rate of ascent and descent is gradient while slope is often used to describe the measurement of the steepness,gradient, incline or grade of a straight line |
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| 9645. |
All important derivation of physics... |
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Answer» All chapters Which chapter ???? I can tell u but from which chapter???? |
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| 9646. |
Difference between real image and virtual image |
| Answer» REAL IMAGE:- 1)light rays actually meet to form a real image. 2) is generally inverted 3)can be obtained on a screen 4) this image is in front of mirror and behind the lens 5) we can reach on it Example....cinema screen............VIRTUAL IMAGE:- 1)light do not actually meet to form virtual image 2) is erect 3) image cannot be obtained on the screen 4)behind the mirror and in front of lens 5) we cannot reach to it Example....our image in plane mirror......hope it will help u? | |
| 9647. |
What is gravitational forcw |
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Answer» The gravitational force is a force that attracts any two objects with mass. We call the gravitational force attractive because it always tries to pull masses together, it never pushes them apart. In fact, every object, including you, is pulling on every other object in the entire universe! This is called Newton\'s Universal Law of Gravitation. The force of attraction between two masses in universe. |
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| 9648. |
Explain the classification according to the elastic properties. |
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| 9649. |
Dopler\'s effect? Please |
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Answer» Wellcome a written THANK YOU for you It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842.A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer. Compared to the emitted frequency, the received frequency is higher during the approach, identical at the instant of passing by, and lower during the recession. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. |
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| 9650. |
Hey! Arrange in increasing order : static, kinetic, limiting friction |
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