1the ans to # 18 is 2 ( a x b )
mole concept
1.who started symbolic representation of elements which we use today
a) dalton b) berzelius
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25 Answers
1yes manmay the ans is 82.4.................plz post the solution
1u cn take for simplicity unit vectors in directions of p,q,r..[1]
1http://questionpaper.in/QuestionPaper.aspx?id=590&bn=46
here we can find previous years bits papers
1jst like taking them as unit vectors in directions of x , y & z axis?
1sakshi simply assume the vector X as a.p+b.q+c.r[1]
now substitute in ur given relation
and equate the various coefficients[1]and hence find value of a,b,c....i hope u cn now finish off the thing!
1let p , q ,r be three mutually perpendicular vectors of same magnitude . if a vector x satisfies the relation
p x [ (x - q) x p ] + q x [ (x -r) x q ] + r x [ ( x-p) x r ] = 0 , then x is given by
a) 1/2 ( p+ q -2r) b) 1/2 (p+q+r ) c ) 1/3 ( p+ q + r ) d ) 1/3 ( 2p + q - r )
1regarding post #17 in terms of wat u want me to answer it???[i mean they must have given options...else there r many possible answers in terms of different vectros.so plz kindly complete the question[1]]
1sakshi i will make things easy for u for this one...[don mind but i m not posting complete solution as i want u to think n develop on these HINTs i m giving]
a cross 2b is perpendicular to a n b.....≈> c is perpendicular to a n b[1]
a x b + b x c + c x a =a x b - b x (a x 2b) +a x(a x 2b)
=4 (a x b)
= -2c
1if a vector a is xpressed as p & q such that p & q r respectively parallel & perpendicular to a vector b then b=?
1a ,b,c r all vectors
a x 2b + c = 0 , then a x b + b x c + c x a = ?
1well from side of manmay i m posting[hope u won't mnd manmay[3]]/
ROH+CH3MgI------>RCH3+Mg(OH)I
now 10-3*4.12/R+17 = 1.12/22400
≈> R=65.4 g
now ROH=65.4+16+1=82.4g
1up the plane T = 2usin (α- β)gcos β
now taking x - axis along the plane, velocity component( when particle strikes the plane) along the plane is 0
so applying equations of motion v = u + at
→ 0 = u cos (α-β) - gsin β .T
→ u cos ( α - β ) = gsin β 2usin (α- β)gcos β
→ 2 tan β = cot ( α - β )
→ 2 tan( α - β ) = cot β
hence ( B) is answer [1]
1another question
A particle is projected at an angle α with the horizontal from the foot of an inclined plane making an angle β with the horizontal. Which of the following holds good if the particle strikes the inclined plane normally?
a)cotβ = tan(α-β)
b)cotβ = 2tan(α-β)
c)cotα = tan(α-β)
d)cotα = 2tan(α-β)
11.12 ml of a gas is produced at S.T.P. BY THE ACTION OF 4.12 mg of alcohol ROH with methyl magnesium iodide ..........the molecular mass of the alcohol is?