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A rocket is fired vertically with a speed of 5 km `s^(-1)` from the earth’s surface. How far from the earth does the rocket go before returning to the earth ? Mass of the earth = `6.0 × 10^(24)` kg; mean radius of the earth = `6.4 × 10^6`m; G = `6.67 × 10^(–11)` N `m^2`

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A man stands on a rotating platform, with his arms stretched horizontally holding a 5 kg weight in each hand. The angular speed of the platform is 30 revolutions per minute. The man then brings his arms close to his body with the distance of each weight from the axis changing from 90cm to 20cm. The moment of inertia of the man together with the platform may be taken to be constant and equal to 7.6 kg `m^2`. (a) What is his new angular speed? (Neglect friction.) (b) Is kinetic energy conserved in the process? If not, from where does

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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The moon is observed from two diametrically opposite points A and B on Earth. The angle θ subtended at the moon by the two directions of observation is `1^o 54′`. Given the diameter of the Earth to be about `1.276 xx 10^7` m, compute the distance of the moon from the

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Fill in the blanks A vehicle moving with a speed of 18 km `h^(–1)` covers....m in 1

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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If Planck’s constant (h ) and speed of light in vacuum (c ) are taken as two fundamental quantities, which one of the following can, in addition, be taken to express length, mass and time in terms of the three chosen fundamental

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Which two of the following five physical parameters have the same dimensions? I. Energy density II. Refractive index III. Dielectric constant IV. Young’s modulus V. Magnetic

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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If `P ,Q, R` are physical quantities, having different dimensions, which of the following combinations can never be a meaningful

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Assertion: When a quantity appears with a power n greater than one in an expression, its error contribution to the final result decreases `n` times. Reason: In all mathematical operations, the errors are not additive in

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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All engineering phenomena deal with definite and measured quantities and so depend on the making of the measurement. We must be clear and precise in making these measurements. To make a measurement, magnitude of the physical quantity (unknown) is compared.The record of a measurement consists of three parts, i.e. the dimension of the quantity, the unit which represents a standard quantity and a number which is the ratio of the measured quantity to the standard quantity.Age of the universe is about `10^(10)` yr, whereas the mankind has existed for `10^6` yr. For how many seconds would the man have existed,

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Maximum absolute error in the sum or difference of two quantities is equal to sum of the absolute error in the individual quantities, i.e.` Z = A + B,` then `± DeltaZ = ± DeltaA ± DeltaB`Maximum fractional error in a product or division of quantities is equal to the sum of fractional errors in the individual quantities `i.e.' 'AB or A/B,` then `(DeltaZ)/Z=+-(DeltaA)/A+(DeltaB)B`Two resistors of resistances `R_1= 100 ± 3Omega and R_2 = 200 ± 4Omega` are connected (a) in series and (b) in parallelThe percentage error in equivalent resistance in series combination

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Maximum absolute error in the sum or difference of two quantities is equal to sum of the absolute error in the individual quantities, i.e.` Z = A + B,` then `± DeltaZ = ± DeltaA ± DeltaB`Maximum fractional error in a product or division of quantities is equal to the sum of fractional errors in the individual quantities `i.e.' 'AB or A/B,` then `(DeltaZ)/Z=+-(DeltaA)/A+(DeltaB)B`Two resistors of resistances `R_1= 100 ± 3Omega and R_2 = 200 ± 4Omega` are connected (a) in series and (b) in parallelFind the equivalent resistance of the parallel combination having error of

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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The expression which shows how and which of the base quantities represent the dimensions of a physical quantity is called the dimensional formula of the given physical quantity. The recognition of concepts of dimensions, which guide the description of physical behaviour is of basic importance as only those physical quantities can be added or subtracted which have the same dimensions. A thorough understanding of dimensional analysis helps us in deducing certain relations among different physical quantities and checking the derivation, accuracy and dimensional consistency or homogeneity of various mathematical expressions. When magnitudes of two or more physical quantities are multiplied,

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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The expression which shows how and which of the base quantities represent the dimensions of a physical quantity is called the dimensional formula of the given physical quantity. The recognition of concepts of dimensions, which guide the description of physical behaviour is of basic importance as only those physical quantities can be added or subtracted which have the same dimensions. A thorough understanding of dimensional analysis helps us in deducing certain relations among different physical quantities and checking the derivation, accuracy and dimensional consistency or homogeneity of various mathematical expressions. When magnitudes of two or more physical quantities are multiplied,

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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The expression which shows how and which of the base quantities represent the dimensions of a physical quantity is called the dimensional formula of the given physical quantity. The recognition of concepts of dimensions, which guide the description of physical behaviour is of basic importance as only those physical quantities can be added or subtracted which have the same dimensions. A thorough understanding of dimensional analysis helps us in deducing certain relations among different physical quantities and checking the derivation, accuracy and dimensional consistency or homogeneity of various mathematical expressions. When magnitudes of two or more physical quantities are multiplied,

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Figure shows the `x-t` plot of a particle in one-dimensional motion. Two different equal intervals of time show speed in time intervals 1 and 2 respectively,

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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A graph of `x` versus `t` is shown in figure. Choose correct statement given

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Match the Column I with Column II and select the correct option from the codes given below. Column I Column II A. `dv'/'dt` p. Acceleration B. `d|v|'/'dt q. Rate of change of speed C. `(d r)/(dt)` r. Velocity D. `(d|r|)/(dt)` s. Magnitude of velocity

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Average Speed and Average Velocity-When an object is in motion, its position changes with time. So, the quantity that describes how fast is the position changing w.r.t. time and in what direction is given by average velocity.It is defined as the change in position or displacement `(Deltax)` divided by the time interval `(Delta t)` in which that displacement occur. However, the quantity used to describe the rate of motion over the actual path, is average speed. It defined as the total distance travelled by the object divided by the total time taken.A truck requires 3 hr to complete a journey

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Assertion: The range of a projectile is maximum at 45°. Reason: At `theta = 45°`, the value of `sin theta` is

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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Uniform Circular Motion When an object follows a circular path at a constant speed, the motion of the object is called uniform circular motion. The word uniform refers to the speed which is uniform (constant) throughout the motion. Although the speed does not vary, the particle is accelerating because the velocity changes its direction at every point on the circular track.The figure shows a particle P which moves along a circular track of radius `r` with a uniform speed `u`.For a particle performing uniform circular motion, choose the incorrect statement from the

asked Mar 19, 2022 in 11th Physics by varun (6.7k points)

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