Questions

Secondary pollutants include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight.

Whereas Primary pollutant are those pollutants that are directly emitted from their sources, like CO2, CO, SO2 as these gases are directly emitted form burning of fossil fuels.

Acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water, sulfuric acid etc.

Hence, Acidrain is a secondary air pollutant.

Maglev trains are used in Japan, South Korea and China only.

Maglev derived from magnetic levitation using the principle of magnetic repulsion is a system of train transportation that uses two sets of magnets, one set to repel and push the train up off the track as in levitation then another set to move the 'floating train' ahead at great speed taking advantage of no friction. Maglev trains are therefore quieter and smoother than conventional trains, and have the potential for much higher speeds

Despite over a century of research and development, maglev transport systems are in operation in just three countries Japan, South Korea and China.

Hence Maglev -- Magnetic-levitation.

Makaibari is the world's first tea factory and was established in 1859 in Darjeeling, West Bengal. 

It is most expensive tea in India which costs around 1.12 lakhs for 1 kg of tea.

Hence, Makaibari is the costliest variety of Tea.

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

M=P(1+i/365)^365n

Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid.

Depending on the nature of the side chain groups, three classes of aminoacids can e distinguished:

1. Amino acids with H ond donor and acceptor groups.

Histidine, lysine, aspartic acid, threonine,...

2. Amino acids with donor grups only.

Arginine, tryptophan and cysteine.

3. Amino acids with acceptor groups only.

Asparagine and glutamine.