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hi faradewaals,
just crosschecked this question from arihant, it seems both tmh as well as fiitjee have printed the question wrongly.
here is the actual question:-
27Al13 is a stale isotope. 29Al13 is expected to disintegrate by:
(a)alpha emission
(b)beta emission
(c)positron emission
(d)proton emission
answer:-
thus extra neutrons are present increasing the n/p ratio.
thus it will disintegrate by converting a neutron into a proton and a beta particle.
thus answer is B.
PS:-
some1 plz tell me how to subscript and superscript. i remember reading somewhere about it, but cant find it again !!!!
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hi admin,
though i agree with you regarding your request to having detailed data regarding portion coverage, i must mention here that this estimate is a very rough one.
Also questions included are from both screening as well as mains. And i think that the screening had only a fraction of the portion of the mains, hence some chapter's importance may appear inflated.
I dont mind calculating and posting the figures, if u insist. But once again, i cannot vouch for its accuracy. And since this will be used by hundreds of goiitians for reference it appears a big risk as to study the entire portion with such figures.
I also agree with 10904him regarding the combining of chapters. Also the changing patterns will also have an impact on these figures.
yours doubtfully,
gau
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tejal
plz make ur question clear
cheers and regards
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hi saket_brutus
u are somewhat right.
gravitation accounts for around 3.75% questions
while fluid mechanics is accounts for around 2.25% questions
asked in the last in the last 25 years.
i have a book from FIITJEE, from which i have made this calculation
PS:- top three lessons according to this book are:-
1>thermodynamics
2>modern physics
3>optics
cheers and regards
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hi kaushal,
if u c the definition of newtons laws, it says they are valid in inertial reference frames only.
thus to apply the newtons laws in non inertial frames, we use the concept of pseudo force.
pseudo = fictitious = non real = a force not due to either gravitational/electrostatic/nuclear interaction
ie, the force is not a real force, but results due to acceleration of the reference frame.(now acc also includes deceleration)
pseudo forces are applied in a direction opposite to acc.
its magnitude = mass times acc
so in a question, 1st check whether the non-inertial frame is accelerating or decelerating, and accordingly decide direction of pseudo force.
cheers & regards......
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hi nunoxic,
components though appear to be tough, simplify things
u can either by heart that the line that makes an angle theta with the vector to be cos, and the angle perpendicular to be sin.
or i suggest u go thru definitions of sin(theta) and cos (theta),
which i suppose u know like the back of your hand. APPLY those definitions by solving on paper, initially u will find very difficult to do it mentally.
regards
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hi vinu,
u got me there, i completely overlooked the absence of the brackets
regards
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Oxidation no of O = -2
now if ox no of Fe were = -2
composition would have been FeO
but Fe is in the ratio Fe(0.93)O(1.00)
thus Fe has some atoms in ox no = +2 and some in +3
say if out of 0.93 if Fe is in +3 ox state of an amount "x"
thus it will be in ox state +2 to an amount "0.93 - x"
thus (3)(x) + (2)(0.93 - x) = (2)(1)
solving,
3x + 1.86 - 2x = 2
x = 0.14
ie out of 0.93, Fe is in +3 state in 0.14 atoms
therefore +3 state %age = (0.14 * 100) /0.93
which comes out to be around 15%
regards
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thanks hdani
please can u get me finar ?
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HI AKSHAY,
i beg to differ from the above answers.
the answer has to be "C".
because, the quantities are different we cannot directly subtract them from each other.
thus the numerator in option C, "P - Q" is ALWAYS meaningless.
hence option C, is 100% positively the correct answer.
while option D, makes sense in a few cases as described above.
regards
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hi suraj,
heres my ans to ur 1st question
it is (4*26) + 50 = 154 mins past 3 o'clock
or 26 min left for 6 o'clock
ie. the time is 5.34pm
plz confirm answer,
gau
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