Recent questions in JEEMAIN and NEET

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

asked Nov 29, 2018 by pady_1

0 answers

A body of mass m = 3.513 kg is moving along the x-axis with a speed of $5.00 ms^{-1}$. The magnitude of its momentum is recorded as

asked Nov 29, 2018 by pady_1

1 answer

Consider a uniform square plate of side ‘a’ and mass ‘m’. The moment of inertia of this plate about an axis perpendicular to its plane and passing through one of its corners is

asked Nov 29, 2018 by pady_1

0 answers

The dimension of magnetic field in M, L, T and C (Coulomb) is given as

asked Nov 29, 2018 by pady_1

0 answers

While measuring the speed of sound by performing a resonance column experiment, a student gets the first resonance condition at a column length of 18 cm during winter. Repeating the same experiment during summer, she measures the column length to be x cm for the second resonance.Then

asked Nov 29, 2018 by pady_1

1 answer

A thin rod of length ‘L’ is lying along the x-axis with its ends at x = 0 and x = L. Its linear density x a(mass/length) varies with X as $K[\frac{X}{L}]$,where n can be zero or any positive number. If the position $X_{CM}$ of the centre of mass of the rod is plotted against ‘n’, which of the following graphs best approximates the dependence of $X_{CM}$ on n?

asked Nov 29, 2018 by pady_1

0 answers

Shown in the figure below is a meter-bridge set up with null deflection in the galvanometer The value of the unknown resistor R is

asked Nov 29, 2018 by pady_1

0 answers

A spherical solid ball of volume V is made of a material of density $p_1$. It is falling through a liquid of density $P_2(p_2 <p_1)$. Assume that the liquid applies a viscous force on the ball that is proportional to the square of its speed v, i.e., $F_{viscous} = -kv^2(k>0).$ The terminal speed of the ball is

asked Nov 29, 2018 by pady_1

0 answers

A planet in a distant solar system is 10 times more massive than the earth and its radius is 10 times smaller. Given that the escape velocity from the earth is $11 kms^{-1}$, the escape velocity from the surface of the planet would be

asked Nov 29, 2018 by pady_1

0 answers

In an experiment, electrons are made to pass through a narrow slit of width â€˜dâ€™ comparable to their de Broglie wavelength. They are detected on a screen at a distance â€˜Dâ€™ from the slit (see figure). Which of the following graph can be expected to represent the number of electrons â€˜Nâ€™ detected as a function of the detector position â€˜yâ€™(y = 0 corresponds to the middle of the slit)?

asked Nov 29, 2018 by pady_1

0 answers

If a strong diffraction peak is observed when electrons are incident at an angle ‘i’ from the normal to the crystal planes with distance ‘d’ between them (see figure), de Broglie wavelength $\lambda_{dB}$ of electrons can be calculated by the relationship (n is an integer)

asked Nov 29, 2018 by pady_1

0 answers

Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see in figure) Electrons accelerated by potential V are diffracted from a crystal. If d = 1Ã… and $i = 30^o$, V should be about $(h = 6.6 \times 10^{-34} Js$, $m_e = 9.1 \times 10^{-31} kg, e = 1.6 \times 10^{-19} C)$

asked Nov 29, 2018 by pady_1

0 answers

The $pK_a$ of a weak acid, HA, is 4.80. The pKb of a weak base, BOH, is 4.78. The pH of an aqueous solution of the corresponding salt, BA, will be

asked Nov 29, 2018 by pady_1

0 answers

The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is

asked Nov 29, 2018 by pady_1

0 answers

The treatment of $CH_3MgX$ with $CH_3C\equiv C-H$ produces

asked Nov 29, 2018 by pady_1

0 answers

The hydrocarbon which can react with sodium in liquid ammonia is

asked Nov 29, 2018 by pady_1

0 answers

Gold numbers of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005, respectively. The correct order of their protective powers is

asked Nov 29, 2018 by pady_1

0 answers

In a compound atoms of element Y from ccp lattice and those of element X occupy 2/3rd of tetrahedral voids. The formula of the compound will be

asked Nov 29, 2018 by pady_1

0 answers

In context with the industrial preparation of hydrogen from water gas $(CO + H_2)$, which of the following is the correct statement?

asked Nov 29, 2018 by pady_1

0 answers

Among the following substituted silanes the one which will give rise to cross linked silicone polymer on hydrolysis is

asked Nov 29, 2018 by pady_1

0 answers

The vapour pressure of water at $20^oC$ is 17.5 mm Hg. If 18 g of glucose $(C_6H_{12}O_6)$ is added to 178.2 g of water at $20^oC$, the vapour pressure of the resulting solution will be

asked Nov 29, 2018 by pady_1

0 answers

Amount of oxalic acid present in a solution can be determined by its titration with $KMnO_4$ solution in the presence of $H_2SO_4$. The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl

asked Nov 29, 2018 by pady_1

0 answers

Given $E^o_{\frac{Cr^3+}{Cr}}=-0.72V$,$E^o_{\frac{Fe^2+}{Fe}}=-0.42V$.The potential for the cell $Cr|Cr^{3+}(0.1 M)| |Fe^{2+}(0.01 M)|Fe$ is

asked Nov 29, 2018 by pady_1

1 answer

Which one of the following is the correct statement?

asked Nov 29, 2018 by pady_1

0 answers

The ionization enthalpy of hydrogen atom is $1.312 \times 10^6 Jmol^{-1}$. The energy required to excite the electron in the atom from n = 1 to n = 2 is

asked Nov 29, 2018 by pady_1

0 answers

Which one of the following pairs of species have the same bond order?

asked Nov 29, 2018 by pady_1

0 answers

Which one of the following constitutes a group of the isoelectronic species?

asked Nov 29, 2018 by pady_1

0 answers

Four species are listed below: i. $HCO_3^{-}$ ii. $H_3O^+$ iii. $HSO_4^{-}$ iv. $HSO_3F$ Which one of the following is the correct sequence of their acid strength?

asked Nov 29, 2018 by pady_1

0 answers

Standard entropy of $X_2, Y_2$ and $XY_3$ are 60, 40 and 50 $JK^{-1}mol^{-1}$, respectively. For the reaction,$\frac{1}{2}X_2+\frac{3}{2}Y_2\rightarrow XY_3,\Delta H=-30KJ$, to be at equilibrium, the temperature will be

asked Nov 29, 2018 by pady_1

0 answers

$\alpha$-D-(+)-glucose and $\beta$-D-(+)-glucose are

asked Nov 29, 2018 by pady_1

0 answers

The electrophile, $E^\oplus$ attacks the benzene ring to generate the intermediate $\sigma$-complex. Of the following, which $\sigma$-complex is of lowest energy?

asked Nov 29, 2018 by pady_1

0 answers

The absolute configuration of

asked Nov 29, 2018 by pady_1

0 answers

For the following three reactions a, b and c, equilibrium constants are given a. $CO(g)+ H_2O(g) =CO_2 (g) + H_2 (g); K_1$ b . $CH_4 (g) + H_2O(g) =CO(g) + 3H_2 (g); K_2$ c. $CH_4 (g) + 2H_2O(g) = CO_2 (g) + 4H_2(g); K_3$ Which of the following relations is correct?

asked Nov 29, 2018 by pady_1

0 answers

Bakelite is obtained from phenol by reacting with

asked Nov 29, 2018 by pady_1

0 answers

Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?

asked Nov 29, 2018 by pady_1

0 answers

Oxidising power of chlorine in aqueous solution can be determined by the parameters indicated below: $\large\frac{1}{2}$$ Cl_2(g) \underrightarrow{\qquad \frac{1}{2} \Delta {diss} H^{-} \qquad } Cl(g) \underrightarrow{\qquad \Delta {eg} H^{-}\qquad} Cl^{-}(g) \underrightarrow{\qquad \Delta _{hyd} H^{-}\qquad } Cl^{-}(aq)$ The energy involved in the conversion of $\frac{1}{2}Cl_2(g) to Cl^{-}(g)$ (using the data , $\Delta_{diss}H^{\Theta}_{Cl_2}=240 KJmol^{-1}$ ,$\Delta_{eg}H^{\Theta}_{Cl}=-349 KJmol^{-1}$ , $\Delta_{hyd}H^{\Theta}_{Cl}=-381 KJmol^{-1}$)

asked Nov 29, 2018 by pady_1

0 answers

The equilibrium constants $K_{p_{1}}$ and $K_{p_{2}}$ for the reactions X = 2Y and Z = P + Q, respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z be equal then the ratio of total pressure at these equilibria is

asked Nov 29, 2018 by pady_1

0 answers

For a reaction $\frac{1}{2}\rightarrow 2B$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the expression

asked Nov 29, 2018 by pady_1

0 answers

At 80oC, the vapour pressure of pure liquid ‘A’ is 520 mm Hg and that of pure liquid ‘B’ is 1000 mm Hg. If a mixture solution of ‘A’ and ‘B’ boils at 80oC and 1 atm pressure, the amount of ‘A’ in the mixture is (1 atm = 760 mm Hg)

asked Nov 29, 2018 by pady_1

0 answers

In which of the following octahedral complexes of Co (at. no. 27), will the magnitude of $\triangle_o$ be the highest?

asked Nov 29, 2018 by pady_1

0 answers

Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being

asked Nov 29, 2018 by pady_1

0 answers

Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives

asked Nov 29, 2018 by pady_1

0 answers

Identify the wrong statements in the following:

asked Nov 29, 2018 by pady_1

0 answers

The coordination number and the oxidation state of the element ‘E’ in the complex $[E(en)_2(C_2O_4)]NO_2$ (where (en) is ethylene diamine) are, respectively,

asked Nov 29, 2018 by pady_1

0 answers

Toluene is nitrated and the resulting product is reduced with tin and hydrochloric acid. The product so obtained is diazotised and then heated with cuprous bromide. The reaction mixture so formed contains

asked Nov 29, 2018 by pady_1

0 answers

The organic chloro compound, which shows complete stereochemical inversion during a $S_N2$ reaction is

asked Nov 29, 2018 by pady_1

0 answers

The quadratic equations $x^2 – 6x + a = 0$ and $x^2 – cx + 6 = 0$ have one root in common. The other roots of the first and second equations are integers in the ratio 4 : 3. Then the common root is

asked Nov 29, 2018 by pady_1

0 answers

27. Let A be a square matrix all of whose entries are integers. Then which one of the following is true?

asked Nov 29, 2018 by pady_1

0 answers

27. Let a, b, c be any real numbers. Suppose that there are real numbers x, y, z not all zero such that x = cy + bz, y = az + cx and z = bx + ay. Then $a^2 + b^2 + c^2 + 2abc$ is equal to

asked Nov 29, 2018 by pady_1

0 answers

27. How many different words can be formed by jumbling the letters in the word MISSISSIPPI in which no two S are adjacent?

asked Nov 29, 2018 by pady_1

0 answers

Ask Questions, Get Answers