Siliceous frustules of diatoms being indestructible, piled up at the bottom of ocean and formed a thick bed over bilions of years. Such a thick bed is known as

Siliceous frustules of diatoms being indestructible, piled up at the bottom of ocean and formed a thick bed over billions of years. Such a thick bed is known as

Siliceous frustules of diatoms being indestructible, piled up at the bottom of ocean and formed a thick bed over billions of years. Such a thick bed is known as

Siliceous frustules of diatoms being indestructible, piled up at the bottom of ocean and formed a thick bed over billions of years. Such a thick bed is known as

How many statements are correct with respect to chrysophytes ? (i) They are found in the marine environment , freshwater organisms are very rare. (ii) In diatoms , the cell wall form two thick overlapping shells which fit together as in a soapbox . (iii) The cell membranes of diatoms are embedded with silica and accumulation of them over billions of years is referred to as "diatomaceous earth " (iv) Diatoms are the chief " Producers" In the oceans .

How many statements are correct with respect to chrysophytes ? (i) They are found in the marine environment , freshwater organisms are very rare. (ii) In diatoms , the cell wall form two thick overlapping shells which fit together as in a soapbox . (iii) The cell membranes of diatoms are embedded with silica and accumulation of them over billions of years is referred to as "diatomaceous earth " (iv) Diatoms are the chief " Producers" In the oceans .

Consider the situation of the previous problem. Assume that the temperature of the water at the botton of the lake remains contant at 4^(@)C as the ice forms on the surface (the heat required to maintain the temperature of the bottom layer may come from the bed of the lake). The depth of the lake is 1.0m. Show that the thickness of the ice formed attains a steady state mamimum value. Find this value. The thermal conductivity of water =0.50Wm ^(-1) ^(@)C^(-1) . Take other relevent data form the previous problelm.