Class 11th

Among the statements (I-IV), the correct ones are:

(I) Be has smaller atomic radius compared to $\mathrm{M}\mathrm{g}$   .

(II) Be has higher ionization enthalpy than Al.

(III) Charge/radius ratio of $\mathrm{B}\mathrm{e}$ is greater than that of $\mathrm{A}\mathrm{l}$ .

(IV) Both Be and Al form mainly covalent compounds.

The incorrect statement(s) among (a) - (d) regarding acid rain is (are):

(a) It can corrode water pipes.

(b) It can damage structures made up of stone.

(c) It cannot cause respiratory ailments in animals

(d) It is not harmful for trees

The strengths of 5.6 volume hydrogen peroxide (of density $1\mathrm{g}/\mathrm{m}\mathrm{L}$ ) in terms of mass percentage and molarity $\left(M\right)$ , respectively, are:

(Take molar mass of hydrogen peroxide as $34\mathrm{g}/\mathrm{m}\mathrm{o}\mathrm{l}$  )

The five successive ionization enthalpies of an element are 800, 2427, 3658, 25024 and $32824\mathrm{k}\mathrm{J}{\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}$ . The number of valence electrons in the element is:

A massless equilateral triangle EFG of side ' $a$ ' (As shown in figure) has three particles of mass $m$ situated at its vertices. The moment of inertia of the system about the line EX perpendicular to $EG$ in the plane of EFG is $\frac{N}{20}m{a}^2$ where $N$  is an integer. The value of $\mathrm{N}$  is                     

If minimum possible work is done by a refrigerator in converting 100 grams of water at $0^{\circ }\mathrm{C}$  to ice, how much heat (in calories) is released to the surroundings at temperature ${27}^{\circ }\mathrm{C}$ (Latent heat of ice $\left.=80\mathrm{C}\mathrm{a}\mathrm{l}/\mathrm{g}\mathrm{r}\mathrm{a}\mathrm{m}\right)$ to the nearest integer?             

A block starts moving up an inclined plane of inclination ${30}^{\circ }$ with an initial velocity of $v_0$

It comes back to its initial position with velocity $\frac{v_0}{2}$   . The value of the coefficient $\frac{v_0}{2}$ kinetic friction between the block and the inclined plane is close to $\frac{1}{1000}$ , The nearest integer to ^$I$  is             .

For a transverse wave traveling along a straight line, the distance between two peaks (crests) is $\mathrm{C}\to \mathrm{I}$ $$ , while the distance between one crest and one trough is $$ $\mathrm{D}\to \mathrm{I}\mathrm{V}$ . The possible wavelengths (in $\mathrm{A}\to \mathrm{I}\mathrm{V};\mathrm{}\mathrm{B}\to \mathrm{I}$ $\mathrm{}$ ) of the waves are:

Match the $C_p/C_V$ ${}_{}{}_{}$ ratio for ideal gases with different type of molecules:

Match the correct option?

A particle is moving unidirectionally on a horizontal plane under the action of a constant power supplying energy source. The displacement(s) - time (t) graph that describes the motion of the particle is (graph are drawn schematically and are not to scale):