List of practice Questions

Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain.

According to the valence bond theory, the metal atom or ion under the influence of ligands can use its (n-1)d, ns, n, nd orbitals for hybridisation to yield a set of equivalent orbitals of definite geometry. These hybridised orbitals are allowed to overlap with ligand orbitals that can donate electron pairs for bonding. It is usually possible to predict the geometry of a complex from the knowledge of its magnetic behaviour on the basis of the valence bond theory. Consider the formation of [Co (NH3)5Cl] Cl2, and answer the following question

The reaction of amines with mineral acids to form ammonium salt shows that these are basic in nature. Amines have an unshared pair of electron on nitrogen atom due to which they behave as lewis base. Basicity of amines is related to their structure. Basic character of an amine depends upon the ease of formation of cation by accepting a proton from the acid. The more stable the cation is relative to the amine. more basic is the amine.

Out of 30 students in a class, 6 like football, 12 like cricket and remaining like tennis. Find the ratio of
(a) Number of students liking football to number of students liking tennis.
(b) Number of students liking cricket to total number of students.

Which of the following reactions follows Markovnikov's rule?

Two plane wavefronts of light, one incident on a thin convex lens and another on the refracting face of a term prism. After refraction at them, the emerging wavefronts respectively become

A charge is moving across a junction, then

Write the mechanism of acid dehydration of ethanol to yield ethene.

In Young’s double-slit experiment using monochromatic light of wavelength $λ$, the intensity of light at a point on the screen where path difference is $λ$, is k units. What is the intensity of light at a point where path difference is $\frac{λ }{3}$?

Find the area of the triangle with vertices $P(4, 5)$, $Q(4, -2)$ and $R(-6, 2)$.

The reaction that takes place when Cl2 gas is passed through conc. NaOH solution is :

Daniel is painting the walls and ceiling of a cuboidal hall with length, breadth and height of 15 m, 10 m and 7 m respectively. From each can of paint 100 m² of area is painted. How many cans of paint will she need to paint the room.

If

\vec{O A} = \vec{a}

and

\vec{O B} = \vec{b}

, then

\vec{B A}

is:

Cost of a dozen pens is ₹ 180 and cost of 8 ball pens is ₹ 56. Find the ratio of the cost of a pen to the cost of a ball pen.

Show that the points (2,3,4),(-1,-2,1),(5,8,7)are collinear.

The probability of obtaining an even prime number on each die when a pair of dice is rolled is:

Find $\frac {dy}{dx}$: $ax+by^2=cos\ y$

If $A$ and $B$ are two events such that $P(A)=\frac{1}{4},P(B)=\frac{1}{2}$ and $P(A∩B)=\frac{1}{8}$,find $P$ (not $A$ and not $B$).

Two cards are drawn at random and without replacement from a pack of 52 playing cards. Find the probability that both the cards are black.

Find the intervals in which the following functions are strictly increasing or decreasing:
$(a) x^2 + 2x − 5 $
$(b) 10 − 6x − 2x^2 $
$(c) −2x^3 − 9x^2 − 12x + 1 $
$(d) 6 − 9x − x^2 $
$(e) (x + 1)^3 (x − 3)^3$

A balloon, which always remains spherical has a variable radius. Find the rate at which its volume is increasing with the radius when the later is 10cm.

If $\sin(sin^{-1}\frac{1}{5}+\cos^{-1}x)=1$ , then find the value of x.

सूची I का सूची II से मिलान कीजिए

	सूची I जल अणुओं की मात्रा सूची		सूची II वर्णन
A	गुरुत्व जल	I	जल का वह भाग जो पादप जड़ों द्वारा आसानी से अवशोषित किया जाता है
B	कोशिकीय जल	II	वह जल जो मृदा के अंदर और बाहर गुरुत्व बल के कारण गति करता है
C	आर्द्रताग्राही जल	III	Water that fills the micropores of the soil
D	उपलब्ध जल	IV	वह जल जो मृदा के कणों से सख्ती से जुड़ा होता है (सक्शन के 31 बार)

निम्नलिखित विकल्पों में से सही उत्तर का चयन कीजिए:

A dip circle is taken to geomagnetic equator. The needle is allowed to move in a vertical plane perpendicular to the magnetic meridian. The needle will stay

If the system of linear equations $ 8 x+y+4 z=-2 $, $ x+y+z=0 $, $ \lambda x-3 y=\mu$ has infinitely many solutions, then the distance of the point $\left(\lambda, \mu,-\frac{1}{2}\right)$ from the plane $8 x + y +4 z +2=0$ is :