Units and Measurements - Class XII

If $1,kg,wt=10,N=F$

Magnetic Flux is defined as the number of magnetic field lines passing through a given closed surface. It gives the measurement of the total magnetic field that passes through a given surface area. S.I. unit of magnetic flux is Weber $(Wb)$.

$1\ cm=0.1\ dm$ or $10\ cm=1\ dm$

Micro is a prefix used in defining some units.  Whenever the word micro is attached as a prefix to an SI unit,  it means it is one million times smaller than that unit. For example, 1 micrometre is one millionth part of a metre. Rest all other options are not   prefixes 

When 'Deca' is attached as a prefix to a unit, it means it is 10 times of that unit.  Kilo means thousand times of a unit.  Femto means of $ {10}^{-15} $ of a unit. Mica is not a prefix but a name of a specific material.

Here femto, atto and zepto, all are used as a prefix in the SI system.

Mega, Hecto and Tera are used as SI prefix. Mega is used for $10^{6}$, Hecto for $10^2$ and Tera for $10^{12}$.

Using linear interpolation: (T - 20) / (150 - 20) = (60 - 0) / (100 - 0). (T - 20) / 130 = 60 / 100 = 0.6. T - 20 = 78, so T = 98.

The melting point of pure ice is $0^0C$. To convert temperature from degree Celsius to Kelvin, we add $273.15$.

Scale X: (50 - 40) / (120 - 40) = 10 / 80 = 1/8. Scale Y: (T_y - (-30)) / (130 - (-30)) = (T_y + 30) / 160. Setting them equal: 1/8 = (T_y + 30) / 160. 20 = T_y + 30. T_y = -10.

The Kelvin scale is an absolute temperature scale that starts at absolute zero (0 K), meaning it does not have negative values.

SI unit of Force is $Newton.$
CGS unit of force is $dyne.$
$1\ N = 1\ kg m/s^{2} = 1000 g \times  100 cm/s^{2} = 100000\ dyne$

Newton is in SI units that is Kg metre per second whereas Dyne is in Gram centimetre per second.

$36\ km h^{-1}=\dfrac{36 km}{1h}=\dfrac{36 \times 1000 m}{60 \times 60 s}$$=10 m s^{-1}$

Impulse $(I)$ imparted to the body is equal to the change in linear momentum $(\Delta p)$ of the body.

CGS unit of density is $g cm^{-3}$

Given, $1 g cm^{-3}=10^3 kgm^{-3}$

$1 ^oA=10^{-10} m=10^{-1}\times 10^{-9} m=0.1 nm$   (as $1 nm=10^{-9}m$)

Here, $1$ milimeter $=10^{-3}$ meter ;

Temperature cannot be expressed in the terms of mass, length and time. Temperature is expressed in kelvin.

Time has same unit, second, in the SI, FPS, CGS and  MKS system. Rest of the quantities have different units in  SI, FPS, CGS and MKS system.

A solar day is the interval from one noon to the next noon.

Magnetic flux is the product of magnetic field and area.

It is given that $x$ is displacement and $t$ is time.
Unit of $x$ is $m$ and that of time t is $s$.
Since, the quantity $Bxt$ must be dimensionless.
$\implies$ Unit of B must be $m^{-1}s^{-1}$.