Name the heartwood which turns golden yellow to darker colour when exposed to light. Write its botanical name, family, origin and areas of cultivation.

Name the "dates of India" and write its origin and area of cultivation.

Write the botanical name, origin, cultivational area and uses of Black gram.

Write the BIOanical name and family of Nilavembu. Write any one of its uses.

Name the cultivated species from which jute is derived. Write the uses of jute.

Read the passage and Answer the following question: In, vacuum the velocity of light radiation with different wavelength is the same. But in a material medium, the velocity of different colour radiations is not the same and they travel with different paths. Due to this, the refractive index of the medium is different for different colours. If white beam of light is incident on a glass prism, the angle of refraction for different colours is different. When Sunlight is incident on a refracting surface, then it gets split into seven coloured spectrum and emerges out. The splitting of light into its component colours is called dispersion. Sir Isaac Newton was the first to use a glass prism to obtain the spectrum of Sunlight. A glass prism is transparent medium bounded by two plane surfaces inclined at an angle. When white light is dispersed into seven colours by a prism, different colours of light bend through different angles with respect to incident ray. Out of these seven colours, red light bends the least, while violet light bends the most. So, the rays of each colour emerge along different paths and becomes distinct. Hence, we get spectrum of seven - different colours. Q. Which light deviates the least and which one deviates the most ?

Read the passage and Answer the following question: In, vacuum the velocity of light radiation with different wavelength is the same. But in a material medium, the velocity of different colour radiations is not the same and they travel with different paths. Due to this, the refractive index of the medium is different for different colours. If white beam of light is incident on a glass prism, the angle of refraction for different colours is different. When Sunlight is incident on a refracting surface, then it gets split into seven coloured spectrum and emerges out. The splitting of light into its component colours is called dispersion. Sir Isaac Newton was the first to use a glass prism to obtain the spectrum of Sunlight. A glass prism is transparent medium bounded by two plane surfaces inclined at an angle. When white light is dispersed into seven colours by a prism, different colours of light bend through different angles with respect to incident ray. Out of these seven colours, red light bends the least, while violet light bends the most. So, the rays of each colour emerge along different paths and becomes distinct. Hence, we get spectrum of seven - different colours. Q. Write the colours of the Spectrum ?