Physical education is an educational course related to maintaining the human body through physical exercises.

A good society is one wherein people enjoy their freedom without compromising on law and order, and everybody is treated equally irrespective of caste, creed, gender, and ethnicity.
A good society cannot manifest in the absence of a constitution, since it is the constitution that makes the supreme laws determining the relationship amidst people living in a territory and also between people and government. Therefore, constitution helps in expressing the aspirations of people about creating a good society.

(i) Drawbacks of Rutherford’s atomic model— According to Rutherford’s model, electrons are orbiting the nucleus ; hence, the direction of their velocity is constantly changing, i.e., the electrons are accelerating. This will cause the electrons to emit or radiate energy; and consequently, the electrons will have lesser and lesser energy will get closer and closer to the nucleus, until at last it spirals into the nucleus.
(ii) An electron moving inward along a spiral path must continuously radiate energy. However in actual practice spectral lines of fixed wavelength are observed.

Δt=time , displacement =Δx
Therefore, shearing stress =Δx/l where l= length
Strain rate=Δx/lΔt
η=shearing stress/strain rate
(F/A)/(Δx/lΔt) = (Fl)/vA where Δx/t=v
Therefore η=(Fl)/ vA

The three distinct components of economics:
(a) Production: It simply means creation of utility. Producer also have limited means while they have a variety of goods and services to choose from. The study of production explains that, as producer, how do they choose such combination, so that their revenue is maximized.
(b) Consumption: It is the process of using up utility, value of goods and services for the direct-satisfaction of our wants. Human wants are unlimited and no one can satisfy his all wants fully because resources to satisfy them are limited. The study of consumption explains that as consumer, how people allocate their income on the purchases of different goods and services so that their satisfaction is maximized
(c) Distribution: The study of distribution explains the economic principle on the basis of which income is distributed among the various factor of productions, how the national income arising from what has been produced in the country is distributed through wages and salaries, profits and interest.

1000 cm³ of 0.15 M Na₂CO₃ contains Na₂CO₃ = 0.15 mol
100 cm³ of 0.15 M Na₂CO₃ Will contain Na₂CO₃ = {tex}\frac { 0.15 } { 1000 } \times 100 = 0.015 \mathrm { mol }{/tex}
Molar mass of Na₂CO₃ = 2 {tex}\times{/tex} Na +1 {tex}\times{/tex} C +3 {tex}\times{/tex}O =2 {tex}\times{/tex}23 +1 {tex}\times{/tex} 12 + 3 {tex}\times{/tex} 16= 46 + 12 + 48 =106 g mol^-1 
Therefore, Mass of Na₂CO₃ =Number of mole of Na₂CO₃ {tex}\times{/tex} Molar mass of Na₂CO₃ = 0.015 mole {tex}\times{/tex}106 g/mol = 1.59 g.