Maths Class -
XII 2000(CBSE) You are on Set no 1 Question 22 to 30
(Students are expected to solve either part B
or part C )
Part B
Q22)
Find the projection of
= 2 - + on = - 2 + .
Q23)
Find the centre and
radius of the following sphere: 2x2 + 2y2 + 2z2 - 4x - 6y + 2z + 3 =
0.
Q24)
Find the magnitude and
direction of resultant of two forces of magnitude 10N and 15N, which are
inclined to each other at an angle of 60o.
Q25)
Find the two like
parallel forces, acting at a distance of 3m apart which is equivalent to a
force 12N acting at a distance of 0.5m from one of the forces.
Q26)
A particle moving with
uniform acceleration passes over 720cm in the 11th second and 960cm in the
15th second of its motion .Find the initial velocity of the
particle.
Q27)
Find so that the four points
with positive vector -6 + 3 +
2 , 3 + + 4, 5 + 7 + 3 and -13 + 17 - are coplanar.
Q28)
Solve the differential
equation: dx/dy = (x + 2y - 1)/(x + 2y + 1)
Q29)
Find the vector equation
of plane passing through the intersection of planes . (2 - 7 + 4) = 3 and . (3 - 5 + 4) + 11 = 0 and passing through the
point (-2, 1, 3)
Q30) A particle is projected with a velocity of 100m/sec, at an
angle of elevation of 30o find: (i) the equation of its
path. (ii) the length of the latus rectum of its path. (iii) the
greatest height attained. (iv) the time of flight and (v) the
horizontal range. [take g = 10m/s2]
Part C
Q22) For a certain distribution the
arithmetic mean is 45, median is 48 and Karl Pearson's coefficient of
Skewness is -0.4. Calculate the S.D. of the distribution.
Q23) An
unbiased coin is tossed 6 times. Find using Binomial distribution, the
probability of getting at least 5 heads.
Q24) Find the present value of an
annuunity of Rs. 1,200 payable at the end of each of 6 month for 3 years
when the interest is earned at 8% per year compounded semi-annually. [Take
(1.04)6 = 1.2653]
Q25) The cost function of a firm is given by C = 4x2
- x + 70 find (i) the average cost (ii) the marginal cost , when x =
3.
Q26) X draws a bill on Y for Rs. 3,000 on 1st March, 1999 payable
after 3 months. The bill is discounted by X, as he is in need of money,
Compute the discount in each of the following cases: (i) The bill is
discounted for Rs 2,840 (ii) The bill is discounted at 8% per
annum.
Q27) Ten percent of bulbs produced in a certain factory turn out to
be defective. Find the probability using poisson distribution, that in a
sample of 10 bulbs chosen at random, (i) Exactly 2 (ii) more than 2 bulbs,
will be defective (Take e-1 =
0.368).
Q28) A began a business unit with Rs. 85,000. After 2 month B
joined with a certain capital. At the end of the year, the profit were
divided in the ratio of 5 : 2. Find how much money was invested by
B.
Q29) A
producer has 30 and 17 units of labour and capital respectively which he
can use to produce two types of goods X and Y. To produce one unit of X ,
2 units of labour and 3 unit of capital are required. Similarly, 3 units
of labour and 1 unit of capital is required to produce one unit of Y. If X
and Y are priced as Rs 100 and Rs 120 per unit respectively, how should
the producer use his resources to maximise the total revenue? Solve the
problem, graphically.
Q30) A
company has two plants to manufacture scooters. Plant - I manufactures 70%
of the scooters and Plant - II manufactures 30%. At Plant - I, 80% of the
scooters are rated of standard quality and at Plant - II 90% of the
scooters are found to be of standard quality. A scooter is chosen at
random and is found to be of standard quality. Find the probability that
it has come from Plant - II.
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