Need for Measurement and Systems of Units

Name the physical quantity whose S.I. unit is $\mathrm{J} {\mathrm{C}}^{-1}$. Is it a scalar or a vector quantity?

The density of material in the CGS system of units is $\frac{4g}{{\mathrm{cm}}^3}$. In a system of units in which unit of length is $10 \mathrm{cm}$ and unit of mass is$100 \mathrm{g}$, the value of density of material will be

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

The ‘rad’ is the correct unit used to report the measurement of

A normal human eye can see an object making an angle of $1.8°$ at the eye. What is the approximate height of object which can be seen by an eye placed at a distance of $1 \mathrm{m}$ from the eye.

Given below are two statements :
Statement I : Astronomical unit (Au), Parsec (Pc) and Light year (ly) are units for measuring astronomical distances.
Statement II : Au < Parsec (Pc) < ly
In the light of the above statements, choose the most appropriate answer from the options given below:

The pitch of the screw gauge is $1 \mathrm{mm}$. There are $100$ divisions on the circular scale when the gap $AB$ is just closed, $8 th$ division of the circular scale coincides with reference line. While measuring the diameter of a wire, the linear scale reads $1 \mathrm{mm}$ and $50 th$ division on the circular scale coincides with the reference line. The length of the wire is $8.6 \mathrm{cm}$. Find the curved surface area of the cylinder.

The solid angle subtended by a spherical section of an area $3{\mathrm{cm}}^2$ at the centre of curvature situated symmetrically at a distance of $7\mathrm{cm}$ from the area is nearly equal to

The density of vanadium is $5.96 \mathrm{g} {\mathrm{cm}}^{-3}$. Convert this quantity to $\mathrm{SI}$ unit of $\mathrm{Kg} {\mathrm{m}}^{-3}$.

Find the value of $20$ joule in a system which has $10 \mathrm{cm},1 \mathrm{kg}$ and $\frac{1}{2}$ minute as fundamental units of length, mass and time.

Which of the following is not an SI unit?

The moon's distance from the earth is $3,60,000\mathrm{kms}$ and its diameter subtends an angle of ${31}^{\text{'}}$ at the eye of the observer. Find the diameter of the moon.

A scooterist covers a distance of $3$ kilometres in $5$ minutes. Calculate his speed in:

(a) centimetres per second $\left(\mathrm{cm} {\mathrm{s}}^{-1}\right)$
(b) metres per second $\left(\mathrm{m} {\mathrm{s}}^{-1}\right)$
(c) kilometres per hour $\left(\mathrm{km} {\mathrm{h}}^{-1}\right)$

The density of vanadium is $5.96 \mathrm{g} {\mathrm{cm}}^{-3}$. Convert this quantity to $\mathrm{SI}$ unit of $\mathrm{Kg} {\mathrm{m}}^{-3}$.

The units that are used for the fundamental physical quantities are called

Unit of time (second) is defined in SI units in terms of:-

The surface tension of water in C.G.S. units is$70 \mathrm{dyne} {\mathrm{cm}}^{-1}$ . It's S.I. unit is

Define 'unit' of a physical quantity. Give SI units for work, power and angular speed.