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10 questions
Transpiration has been described as a ‘necessary evil’ because it is inevitable, but potentially harmful. Which of the following are the after-effects of transpiration?
(i) Absorption of mineral salts.
(ii) Regulation of plant temperature.
(iii) Energy deficit and injury in plants.
(iv) Ascent of sap.
(i) & (iv)
(i) & (iii)
(i), (ii) & (iii)
(i), (ii) & (iv)
A simplified food chain for an aquatic environment is shown below: algae → mosquito larvae → small fish → large fish If the number of mosquito larvae suddenly increased, the food chain would be affected. Analyze the following consequences and select from the choices what would be the impact?\
I. The number of small fish would increase.
II. The number of large fish would decrease.
III. The number of large fish would increase.
IV. Amount of algae would decrease.
Only I
Only IV
Both I and IV
Both II and IV
A roller coaster begins at rest from point A, 120 m above the ground, as shown in figure. Assume that no energy is lost from the coaster to frictional heating, air resistance, sound, or any other process. The radius of the loop is 40 m. (take g=10 m/s2 ). The speed of the roller coaster at points B and D are respectively
34 m/s, 28 m/s
28 m/s, 34 m/s
17 m/s, 14 m/s
17 m/s, 0
Chlorine gas reacts with _______ to form bleaching powder.
dry slaked lime
dil. solution of Ca(OH)2
conc. solution of Ca(OH)2
dry calcium oxide
Baking powder is different from baking soda as it also contains a small quantity of edible acid. The presence of the edible acid decreases bitterness of baking soda. Which acid is present in baking powder?
sulphuric acid
acetic acid
tartaric acid
malic acid
Hawks and eagles are often reported to die due to pesticide poisoning, but pigeons are not. The phenomenon responsible for this is:
Eutrophication
Pollution
Biomagnification
Accumulation
Figure here shows speed-time graph for a car moving in a straight line. At which point is its acceleration non-uniform?
A
B
C
D
The angle of incidence on mirror B is
200
500
600
700
Potassium iodide and lead nitrate solutions are mixed in a test tube to form lead iodide and potassium nitrate. Which of the following correctly represents/represent the type/types of the reaction (s) involved?
i) Displacement reaction
ii) Precipitation reaction
iii) Combination reaction
iv) Double displacement reaction
iv only
ii only
both i and ii
both ii and iv
Four aluminum rods A, B, C & D of different dimensions are given in the picture. Which will have the least resistance?
A
B
C
D
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