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Biology; Chemistry; Physics: Post your doubts here!

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39. it is d because first the nitrate content increases which the algae use to grow rapidly ..... so they block off light and the plants die ...... this increases food for decomposing bacteria which rapidly use up oxygen
34. its a because in alloys the larger atom with larger radius disrupts the arrangement of the metal atoms with smaller radius so that their layers can not slide over each other making them hard and strong....
39 : but why decrease in dissolved o2 and then death of aquatic plants? isn't it that decrease in o2 is because of plant death as bacteria respire aerobically. but why in this phele 4 is written?
 
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39 : but why decrease in dissolved o2 and then death of aquatic plants? isn't it that decrease in o2 is because of plant death as bacteria respire aerobically. but why in this phele 4 is written?
the algae use up oxygen rapidly since they are numerous in number ... so due to lack of oxygen the plants die ............
 
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:sigh:
AoA
thank God i didnt waste my time vainly here...
well,
To that ABC drinks wala Q, they asked about suggestions. and when it comes to suggestions, there can more than 1 possible answer. So, both A and C can be correct with logical explanation.

and what about that Precautions wala MCQ? the one with PQRS precautions? at first i did A, then i changed it to C, wbu guys?
 
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Which statement about the action of a transformer is correct?
A An alternating current always flows in the secondary coil when an alternating voltage is
applied to the primary coil.
B The current in the secondary coil is always larger than the current in the primary coil.
C An e.m.f. is induced in the secondary coil when an alternating voltage is applied to the
primary coil.
D An e.m.f. is induced in the secondary coil when a steady direct current flows in the primary
coil.


whats wrong with A
 
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Which statement about the action of a transformer is correct?
A An alternating current always flows in the secondary coil when an alternating voltage is
applied to the primary coil.
B The current in the secondary coil is always larger than the current in the primary coil.
C An e.m.f. is induced in the secondary coil when an alternating voltage is applied to the
primary coil.
D An e.m.f. is induced in the secondary coil when a steady direct current flows in the primary
coil.

whats wrong with A
when an alternating current is applied, the primary coil may also contain diodes, so Alternating current does not ALWAYS flows in secondary coil.

answer is C, right?
 
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:sigh:
AoA
thank God i didnt waste my time vainly here...
well,
To that ABC drinks wala Q, they asked about suggestions. and when it comes to suggestions, there can more than 1 possible answer. So, both A and C can be correct with logical explanation.

and what about that Precautions wala MCQ? the one with PQRS precautions? at first i did A, then i changed it to C, wbu guys?
the correct option was the one that rejected "the dot of liquid should be at far right of capillary tube"
i think it was D.....
 
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why reject that? o_O
rate of respiration is to be seen(the question said so)
this is seen by looking at the CO2 release...
if the dot is at very right...the CO2 will apply pressure on it and either throw it out of the tube or just not give a change in reading.
the dot needs to be as close as possible to the apparatus as the distance the CO2 travels to the right is to be measured.....
i hope you do understand :)
 
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rate of photosynthesis is to be seen(the question said so)
this is seen by looking at the CO2 release...
if the dot is at very right...the CO2 will apply pressure on it and either throw it out of the tube or just not give a change in reading.
the dot needs to be as close as possible to the apparatus as the distance the CO2 travels to the right is to be measured.....
i hope you do understand :)
that was about anaerobic respiration of yeast! :eek:
which variant are you?
 
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