Units and Dimensions

IMPORTANT

Units and Dimensions: Overview

This topic covers concepts, such as, Dimensions, Dimensions of Fundamental Quantities, Physical Quantity as Vectors & Physical Quantity as Tensors etc.

Important Questions on Units and Dimensions

EASY
IMPORTANT

Name the physical quantity whose S.I. unit is J C1. Is it a scalar or a vector quantity?

EASY
IMPORTANT

The density of material in the CGS system of units is 4gcm3. In a system of units in which unit of length is 10 cm and unit of mass is100 g, the value of density of material will be

MEDIUM
IMPORTANT

The density of material in the CGS system of units is  4 g cm-3. In a system of units in which unit of  length is 10 cm and the unit of  mass  is 100 g, the value of density of the material will be

MEDIUM
IMPORTANT

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

MEDIUM
IMPORTANT

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

EASY
IMPORTANT

The dimension of 1 2 ε 0 E 2 , where   ε 0 is permittivity of free space and E is electric field, is:

MEDIUM
IMPORTANT

Which two of the following five physical parameters have the same dimensions?
(A) Energy density
(B) Refractive index
(C) Dielectric constant
(D) Young’s modulus
(E) Magnetic field

EASY
IMPORTANT

Dimensions of resistance in an electrical circuit in terms of dimension of mass M, length L, time T and current I, would be

EASY
IMPORTANT

The ratio of the dimensions of Planck’s constant and that of the moment of inertia has the dimensions of

EASY
IMPORTANT

The unit of the Stefan - Boltzmann’s constant is

EASY
IMPORTANT

The dimensions of Planck’s constant are same as

EASY
IMPORTANT

Which one of the following groups have quantities that do not have the same dimensions?

EASY
IMPORTANT

The dimensional formula for magnetic flux is

EASY
IMPORTANT

The force F on a sphere of radius a moving in a medium with velocity v is given by   F=6πηav.  The dimensions of   η  are

EASY
IMPORTANT

Which of the following will have the dimensions of time?

EASY
IMPORTANT

An equation is given as : ( P+ a V 2 )=b θ V , where P=Pressure,V=Volumeandθ=Absolute temperature. If a and b are constant, then dimensions of ‘a’ will be:

EASY
IMPORTANT

An equation is given as : ( P+ a V 2 )=b θ V , where P=Pressure,V=Volumeandθ=Absolute temperature. If a and b are constant, then dimensions of ‘a’ will be:

EASY
IMPORTANT

The dimensional formula of pressure is:

MEDIUM
IMPORTANT

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:

EASY
IMPORTANT

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 the constant, called coefficient of viscosity. The dimensional formula of η is