Questions

Settled agriculture was first seen in China around 6000 BC. The crops grown at this time were rice and millet.

Beginning in about 618 BC with classical millet agriculture, China's development of farming over the course of its history has played a key role in supporting the growth of what is now the largest population in the world.

1st copper wire: R = pl/A = pl/ πr2

2ndcopper wire: R’ = p’l’/A’ = pl/(4 πr2) = R/4

If joined in parallel, (1/Req) = (1/R) + (1/R’)

= 1/R + 4/R1/Req= 5/R

Req= R/5

Dry ice or Cardice is the solid form of Carbon dioxide.

1. It has an advantage of lower temperature than the water ice and doesn't leave any residue.

2. The reason why it is called as Dry ice is because unlike the normal ice, it won't melt into liquid form. It directly evaporates into the air as gas. That is Solid to gas form passing through liquid state is a phenomenon called as Sublimation.

3. The primary use of dry ice is as cooling agent.

Antarctica is known as white continent because 98% of it's area is covered by ice throughout the year.

The ability to target combinations of countries, territories, and regions.