Dimensions of Physical Quantities and Dimensional Analysis

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Dimensions of Physical Quantities and Dimensional Analysis: Overview

In this topic, we will understand how to write the dimensions of physical quantities. It highlights the dimensional formulae of some physical quantities in tabular form. It also mentions the uses of the dimensional equation to derive the dimensions.

Important Questions on Dimensions of Physical Quantities and Dimensional Analysis

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The dimensions of  ( μ 0 ε 0 ) 1 2 are

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The dimensions of    ( μ 0 ε 0 ) 1 2 are

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The frequency of vibration f of a mass m suspended from a spring of spring constant k is given by a relation of the type f=cmxky , where c is a dimensionless constant. The values of x and y are:

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According to Newton, the viscous force acting between liquid layers of area A and velocity gradient  ΔvΔz is given by F=-ηAΔvΔz, where η is constant called coefficient of viscosity. The dimensional formula of η is:

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If C and R denote capacitance and resistance respectively, then the dimensional formula of CR is

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Turpentine oil is flowing through a tube of length l and radius r. The pressure difference between the two ends of the tube is p. The viscosity of oil is given by

                          η= p( r 2 x 2 ) 4vl

Where v is the velocity of oil at a distance x from the axis of the tube. The dimensions of   η are:

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P represents radiation pressure, c represents speed of light and S represents radiation energy striking unit area per sec. The non zero integers x, y, z such that  PxSycz is dimensionless are:

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The dimensional formula of the constant a in Vander Waal’s gas equation   ( P+ a V 2 )(Vb)=RT  is:

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The dimensional formula of the constant a in Vander Waal’s gas equation   ( P+ a V 2 )(Vb)=RT  is:

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Pressure depends on distance as P=α β exp-αzkθ, where α,β are constants z is distance, k is Boltzman's constants and θ is temperature. The dimension of β are

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The units of force and length are made three times of their earlier values. Earlier the energy of energy of the system was 81 J. What will be the energy of the same system in new units?

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If speed of light c, acceleration due to gravity g and pressure p are taken as fundamental units, the dimensions of gravitational constant G are

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The speed of light c, gravitational constant G, and Planck's constant h are taken as the fundamental units in a system. The dimension of time in this new system should be,

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The pair(s) of physical quantities that have same dimension, is (are):

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The dimensions of the quantities in one (or more) of the following pairs are the same. Identify the pair(s).

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L, C and R represent the physical quantities, inductance, capacitance and resistance, respectively. The combinations which have the dimensions of frequency are

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Which of the following physical quantities have the same dimensions ?

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Which of the following quantities has the S.I. unit kg m2 s-3 A-2?