List of practice Questions

$ \displaystyle\lim _{n \rightarrow \infty} n \sin \frac{2 \pi}{3 n} \cdot \cos \frac{2 \pi}{3 n}$ is

If $y =tan ^{-1} \sqrt {x^2-1}$ then the ratio $\frac {d^2y}{dx^2}: \frac {dy}{dx}$=_________

Sporopollenin, a chemical substance is found in________

Which of the following is NOT true?

The following diagrams A, B, C, D and E show the different types of arrangement of stamens based on the cohesion of their parts in different plants. Assign the stamens to their respective plants. Choose the correct answer.

The sides of a triangle are $6+\sqrt {12} , \sqrt {48} $ and $\sqrt {24}$. The tangent of the smallest angle of the triangle is

The presence of corollary corona, sagittate anthers and dumb-bell shaped stigma are the characteristic features of_____________

The locus of the point of intersection of the tangents drawn at the ends of a focal chord of the parabola $x^2=-8y$ is _______

Oxidation states of $P$ in $ H_4 \, P_2 \, O_5, H_4, P_2, O_6 , H_4 P_2 O_7 $ respectively are

In which of the following situations, is there a risk factor for children of incurring Erythroblastosis foetalis?

Some of the steps involved in the production of Humulin are given below. Choose the correct sequence. i) Synthesis of gene (DNA) for human insulin artificially. ii) Culturing recombinant E.coli in bioreactors. iii) Purification of humulin. iv) Insertion of human insulin gene into plasmid. v) Introduction of recombinant plasmid into E.coli. vi) Extraction of recombinant gene product from E.coli.

In C4 pathway, the CO2 fixation in mesophyll cells is carried out by the enzyme .........

The rate of the reaction $ {2NO + Cl_2 -> 2NOCl}$ is given by the rate equation rate = $ { k[NO]^2[Cl_2]}$ . The value of the rate constant can be increased by -

Which one of the following does not involve coagulation?

A motorboat covers a given distance in $6$ hours moving downstream on a river. It covers the same distance in $10$ hours moving upstream. The time it takes to cover the same distance in still water is..........

Two thick wires and two thin wires, all of same material and same length, form a square in three different ways $P, Q$ and $R$ as shown in the figure. With correct connections shown, the magnetic field due to the current flow, at the centre of the loop will be zero in case of...........

There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then

$ N_{2} $ gas will not be evolved upon reaction of $ HNO_3$ with which of the following amines?

The attenuation in optical fibre is mainly due to

In a buffer solution containing equal concentration of $ B^- $ and HB, the $ K_b $ for $ B^- $ is $ 10^{-10} $ . The pH of buffer solution is

The points $(1, 0), (0, 1), (0, 0) $ and $ (2k, 3k),k \neq 0$ are concyclic if $k$ = _____

What is $ [H^+] $ in mol/L of a solution that is $0.20 \,M$ in $ CH_3COONa $ and $0.10 \,M$ in $ CH_3COOH $ ? $ (K_a\, \, for\, \, CH_3COOH = 1.8 \times 10^{-5}) $

Hot water cools from $60^{\circ}C$ to $50^{\circ}C$ in the first $10$ minutes and to $42^{\circ}C$ in the next $10$ minutes. Then the temperature of the surroundings is

Match the animals listed in Column I with their of nature of blood listed in Column II. Choose the answer which gives the correct combination of alphabets of the two columns

A mixture of $CaCl_2$ and $NaCl$ weighing $4.44\, g$ is treated with sodium carbonate solution to precipitate all the calcium ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get $0.56\, g$ of $CaO$. The percentage of $NaCl$ in the mixture is (Atomic mass of $Ca = 40)$