Rishab has arranged the following set-ups to study the process of rusting.
Iron nail will rust in test tubes
Important Questions on SOF National Science Olympiad
Match the following columns for the flame of a candle.
|
Column I (Part) |
Column II (Zone) |
Column III (Colour) |
| P. Hottest part | (i) Innermost zone of unburnt wax vapours | (x) Blue |
| Q. Moderately hot part | (ii) Middle zone of partial combustion | (y) Black |
| R. Least hot part | (iii) Outermost zone of complete combustion | (z) Yellow |
Following statements are given by four students:
Rashmi : Sodium chloride is an acidic salt whereas washing soda is a basic salt.
Akshi : The aqueous solution of sugar does not change the colour of either red litmus solution or blue litmus solution.
Reema : Tamarind tastes sour whereas baking soda is bitter in taste.
Shristi : Apple juice does not change the colour of red litmus solution.
The incorrect statement(s) is/are given by
Statement 1 : Bakelite is used for making electric switches and plugs.
Statement 2 : It is a thermosetting polymer and an insulator.
I. Perspex is thermoplastic which is transparent like glass but is much stronger.
II. Nylon thread cannot support more weight as compared to steel wire of same dimensions.
III. Polyester and nylon on burning give smell of burning hair.
IV. Terylene, a synthetic fibre, can be used instead of wool.
Given below is a list of few chemicals that are used for protection of crops
(i) Dalapon
(ii) Butachlor
(iii) Malathion
(iv) Simazine
(v) Disyston
(vi) Gammexane
How many of these are used as insecticides?
Refer to the given figures and select the incorrect statement regarding them.
