Recent questions in 2008

In the following sequence of reactions, the alkene affords the compound ‘B’ $CH_3CH = CHCH_3 \xrightarrow{O_3} A \xrightarrow[\text{Zn}]{\text{$H_2O$}} B$ The compound is :

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An insulated container of gas has two chambers separated by an insulating partition. One of the chambers has volume V1 and contains ideal gas at pressure $P_1$ and temperature $T_1$. The other chamber has volume $V_2$ and contains ideal gas at pressure $P_2$ and temperature $T_2$. If the partition is removed without doing any work on the gas, the final equilibrium temperature of the gas in the container will be

asked Nov 29, 2018 by pady_1

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Two full turns of the circular scale of a screw gauge cover a distance of 1 mm on its main scale. The total number of divisions on the circular scale is 50. Further, it is found that the screw gauge has a zero error of - 0.03 mm while measuring the diameter of a thin wire, a student notes the main scale reading of 3 mm and the number of circular scale divisions in line with the main scale as 35. The diameter of the wire is

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Relative permittivity and permeability of a material are $\varepsilon_r$ and $\mu_r$, respectively. Which of the following values of these quantities are allowed for a diamagnetic material?

asked Nov 29, 2018 by pady_1

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A horizontal overhead power line is at a height of 4m from the ground and carries a current of 100 A from east to west. The magnetic field directly below it on the ground is $(\mu_0 = 4\pi\times 10^{-7} T m A^{-1})$

asked Nov 29, 2018 by pady_1

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A 5V battery with internal resistance $2\Omega$ and a 2V battery with internal resistance $1\Omega$ are connected to a $10\Omega$ resistor as shown in the figure. The current in the $10\Omega$ resistor is <img src""/>

asked Nov 29, 2018 by pady_1

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A thin spherical shell of radius R has charge Q spread uniformly over its surface. Which of the following graphs most closely represents the electric field E(r) produced by the shell in the range $0\leq r\infty$, where r is the distance from the centre of the shell?

asked Nov 29, 2018 by pady_1

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An experiment is performed to find the refractive index of glass using a travelling microscope. In this experiment distance are measured by

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A body is at rest at x = 0. At t = 0, it starts moving in the positive x-direction with a constant acceleration. At the same instant another body passes through x = 0 moving in the positive x- direction with a constant speed. The position of the first body is given by $x_1$(t) after time ‘t’ and that of the second body by $x_2$(t) after the same time interval. Which of the following graphs correctly describes $(x_1 – x_2)$ as a function of time ‘t’?

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In the circuit below, A and B represent two inputs and C represents the output <img src""/> The circuit represents

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Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross sectional area $A = 10 cm^2$ and length = 20 cm. If one of the solenoids has 300 turns and the other 400 turns, their mutual inductance is ($\mu_0= 4\pi \times 10^{-7} Tm A^{-1}$)

asked Nov 29, 2018 by pady_1

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A wave travelling along the x-axis is described by the equation y(x, t) = 0.005 cos ($\alpha x-\beta t$). If the wavelength and the time period of the wave are 0.08 m and 2.0 s, respectively, then $\alpha$ and $\beta$ in appropriate units are

asked Nov 29, 2018 by pady_1

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Suppose an electron is attracted towards the origin by a force k/r where ‘k’ is a constant and ‘r’ is the distance of the electron from the origin. By applying Bohr model to this system, the radius of the nth orbital of the electron is found to be $‘r_n’$ and the kinetic energy of the electron to be $T_n$. Then which of the following is true?

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A capillary tube (A) is dropped in water. Another identical tube (B) is dipped in a soap water solution. Which of the following shows the relative nature of the liquid columns in the two tubes?

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A block of mass 0.50 kg is moving with a speed of 2.00 m/s on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

asked Nov 29, 2018 by pady_1

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91. A student measures the focal length of convex lens by putting an object pin at a distance ‘u’ from the lens and measuring the distance ‘v’ of the image pin. The graph between ‘u’ and ‘v’ plotted by the student should look like

asked Nov 29, 2018 by pady_1

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Consider a block of conducting material of resistivity â€˜pâ€™ shown in the figure. Current â€˜Iâ€™ enters at â€˜Aâ€™ and leaves from â€˜Dâ€™. We apply superposition principle to find voltage â€˜$\triangle$Vâ€™ developed between â€˜Bâ€™ and â€˜Câ€™. The calculation is done in the following steps: (i) Take current â€˜Iâ€™ entering from â€˜Aâ€™ and assume it to spread over a hemispherical surface in the block (ii) Calculate field E(r) at distance â€˜râ€™ from A by using Ohmâ€™s law E = pj, where j is the current per unit area at â€˜r (iii) From the â€˜râ€™ dependence of E(r), obtain the potential V(r) at r. (iv) Repeat (i), (ii) and (iii) for current â€˜Iâ€™ leaving â€˜Dâ€™ and superpose results for â€˜Aâ€™ and â€˜Dâ€™. QUESTION : For current entering at A, the electric field at a distance â€˜râ€™ from A is

asked Nov 29, 2018 by pady_1

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Consider a block of conducting material of resistivity â€˜pâ€™ shown in the figure. Current â€˜Iâ€™ enters at â€˜Aâ€™ and leaves from â€˜Dâ€™. We apply superposition principle to find voltage â€˜$\triangle$Vâ€™ developed between â€˜Bâ€™ and â€˜Câ€™. The calculation is done in the following steps: (i) Take current â€˜Iâ€™ entering from â€˜Aâ€™ and assume it to spread over a hemispherical surface in the block (ii) Calculate field E(r) at distance â€˜râ€™ from A by using Ohmâ€™s law E = pj, where j is the current per unit area at â€˜r (iii) From the â€˜râ€™ dependence of E(r), obtain the potential V(r) at r. (iv) Repeat (i), (ii) and (iii) for current â€˜Iâ€™ leaving â€˜Dâ€™ and superpose results for â€˜Aâ€™ and â€˜Dâ€™. QUESTION : $\triangle$V measured between B and C is

asked Nov 29, 2018 by pady_1

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78. A working transistor with its three legs marked P, Q and R is tested using a multimeter. No conduction is found between P and Q. By connecting the common (negative) terminal of the multimeter to R and the other (positive) terminal to P or Q, some resistance is seen on the multimeter. Which of the following is true for the transistor?

asked Nov 29, 2018 by pady_1

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A jar filled with two non mixing liquids 1 and 2 having densities $p_1 and P_2$ respectively. A solid ball, made of a material of density $p_3$, is dropped in the jar. It comes to equilibrium in the position shown in the figure.Which of the following is true for $P_1, p_2\; and\; p_3$?,

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This question contains Statement -1 and Statement-2. Of the four choices given after the statements, choose the one that best describes the two statements. Statement – I: For a mass M kept at the centre of a cube of side ‘a’, the flux of gravitational field passing through its sides is $4\pi GM.$. and Statement – II If the direction of a field due to a point source is radial and its dependence on the distance ‘r’ for the source is given as $\frac{1}{r^2}$,its flux through a closed surface depends only on the strength of the source enclosed by the surface and not on the size or shape of the surface

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This question contains Statement -1 and Statement-2. Of the four choices given after the statements, choose the one that best describes the two statements. Statement – I: Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion. and Statement – II For heavy nuclei, binding energy per nucleon increases with increasing Z while for light nuclei it decrease with increasing Z.

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The speed of sound in oxygen $(O_2)$ at a certain temperature is $460 ms^{-1}$. The speed of sound in helium (He) at the same temperature will be (assumed both gases to be ideal)

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78. A parallel plate capacitor with air between the plates has a capacitance of 9 pF. The separation between its plates is ‘d’. The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant $K_1=3$ and thickness $\frac{d}{3}$ while the other one has dielectric constant $K_2 = 6$ and thickness $\frac{2d}{3}$. Capacitance of the capacitor is now

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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

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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

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

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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?

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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

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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

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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

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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

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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

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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

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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

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

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

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The hydrocarbon which can react with sodium in liquid ammonia is

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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

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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

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

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

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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

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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

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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

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1 answer

Which one of the following is the correct statement?

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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

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

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In the following sequence of reactions, the alkene affords the compound ‘B’ $CH_3CH = CHCH_3 \xrightarrow{O_3} A \xrightarrow[\text{Zn}]{\text{$H_2O$}} B$ <br> The compound is :

Relative permittivity and permeability of a material are $\varepsilon_r$ and $\mu_r$, respectively. Which of the following values of these quantities are allowed for a diamagnetic material?

A horizontal overhead power line is at a height of 4m from the ground and carries a current of 100 A from east to west. The magnetic field directly below it on the ground is $(\mu_0 = 4\pi\times 10^{-7} T m A^{-1})$

A 5V battery with internal resistance $2\Omega$ and a 2V battery with internal resistance $1\Omega$ are connected to a $10\Omega$ resistor as shown in the figure. The current in the $10\Omega$ resistor is<br> <img src""/>

A thin spherical shell of radius R has charge Q spread uniformly over its surface. Which of the following graphs most closely represents the electric field E(r) produced by the shell in the range $0\leq r\infty$, where r is the distance from the centre of the shell?

An experiment is performed to find the refractive index of glass using a travelling microscope. In this experiment distance are measured by

In the circuit below, A and B represent two inputs and C represents the output <br> <img src""/><br> The circuit represents

Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross sectional area $A = 10 cm^2$ and length = 20 cm. If one of the solenoids has 300 turns and the other 400 turns, their mutual inductance is ($\mu_0= 4\pi \times 10^{-7} Tm A^{-1}$)

A wave travelling along the x-axis is described by the equation y(x, t) = 0.005 cos ($\alpha x-\beta t$). If the wavelength and the time period of the wave are 0.08 m and 2.0 s, respectively, then $\alpha$ and $\beta$ in appropriate units are

A capillary tube (A) is dropped in water. Another identical tube (B) is dipped in a soap water solution. Which of the following shows the relative nature of the liquid columns in the two tubes?

A block of mass 0.50 kg is moving with a speed of 2.00 m/s on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

91. A student measures the focal length of convex lens by putting an object pin at a distance ‘u’ from the lens and measuring the distance ‘v’ of the image pin. The graph between ‘u’ and ‘v’ plotted by the student should look like

A jar filled with two non mixing liquids 1 and 2 having densities $p_1 and P_2$ respectively. A solid ball, made of a material of density $p_3$, is dropped in the jar. It comes to equilibrium in the position shown in the figure.Which of the following is true for $P_1, p_2\; and\; p_3$?,<br>

The speed of sound in oxygen $(O_2)$ at a certain temperature is $460 ms^{-1}$. The speed of sound in helium (He) at the same temperature will be (assumed both gases to be ideal)

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

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

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

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

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

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

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

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)

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

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

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

The hydrocarbon which can react with sodium in liquid ammonia is

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

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

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

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

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

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

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

Which one of the following is the correct statement?

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

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