Recent questions tagged jeemain

what is the correct order of spin only magnetic moment (in BM) of $Mn^{2+},Cr^{2+}$ and $ V^{2+}?$

asked Oct 29, 2013 by meena.p

1 answer

The standard reduction potentials of $Zn^{2-} |Zn,Cu^{2+}|Cu$ and $Ag^{+} | Cu\;and\;Ag^{+}|Ag$ are respectively $-0.76,0.34$ and $0.8\;V$. The following cells were constructed :

asked Oct 29, 2013 by meena.p

1 answer

Consider a p-n junction as a capacitor, formed with p and n-materials acting as thin metal electron and depletion layer width acting as separation between them. Basing on this , assume that n-p-n transistor is working as an amplifier in CE configuration . If $C_1$ and $C_2$ are the base - emitter and collector- emitter junction capacitances, then:

asked Oct 29, 2013 by meena.p

1 answer

A free neutron decays spontaneously into:

asked Oct 29, 2013 by meena.p

1 answer

A proton, a deuteron (nucleus of $_1 H^2$) and an $\alpha$- particle with same kinetic energy enter a region of uniform magnetic field moving at right angles to the field. The ratio of the radii of their circular paths is :

asked Oct 29, 2013 by meena.p

1 answer

A oil drop having a mass $4.8 \times 10^{10}\;g$ and charge $2.4 \times 10^{-18}\;C$ stands still between two charged horizontal plates separated by a distance of 1 cm. If now the polarity of the plates is changed, instantaneous acceleration of the drop is : $(g= 10 ms^{-2}$)

asked Oct 29, 2013 by meena.p

1 answer

A small square loop of wire of side i is placed inside a large square loop of slide $L( L >>1)$. If the loops are coplanar and there centers coinside. the mutual induction of the system is directly proportional to :

asked Oct 29, 2013 by meena.p

1 answer

A rectangular loop of length l and breadth b is placed at distance of x from infinitely long wire carrying current i such that the direction of current is parallel to breadth. If the loop moves away from the current wire in a direction perpendicular to it with a velocity v, the magnitude of the emf in the loop is : ($\mu_o$= permeability of free space)

asked Oct 29, 2013 by meena.p

1 answer

When positively charged particle enters a uniform magnetic field with uniform velocity, its trajectory can be :

asked Oct 29, 2013 by meena.p

1 answer

If the cold junction is held at $0^{\circ}$, the same thermo emf V of a thermocouple varies as $V= 10 \times 10^{-6} t -\large\frac{1}{40} \times 10^{-6}t^2$, Where t is the temperature of the hot junction in $^{\circ}C$. The neutral temperature and the maximum value of thermo emf are respectively:

asked Oct 29, 2013 by meena.p

1 answer

Twelve cells, each having emf E volts are connected in series and are kept in a closed box. Some of these cells are wrongly connected with positive and negative terminals reversed. This 12 cell battery is connected in series with an ammeter , an external resistance R ohms and a two- cell battery (two cells of the same type used earlier , connected perfectly in series). The current in the circuit when the 12 - cell battery and 2-cell battery aid each other is 3A and is 2A when they oppose each other . Then, the number of cells in 12 -cell battery that are connected wrongly is :

asked Oct 29, 2013 by meena.p

2 answers

One end of each of a resistance r capacitor C and resistance 2r are connected together. The other ends are respectively connected to the positive terminals of batteries, P, Q, R having respectively emf's E,E and 2E. The negative terminals of the batteries are then connected together. In this circuit, with steady current the potential drop across the capacitor is :

asked Oct 29, 2013 by meena.p

1 answer

Two solution of a substance (non-electrolyte) are mixed in the following manner,480ml of 0.5M of first solution with 520 ml of 1.2m of second solution.The molarity of final solution is

asked Oct 29, 2013 by sreemathi.v

1 answer

Along the X-axis, three charges $\large\frac{q}{2},-q$ and $\large\frac{q}{2}$ are placed at $x=0,x= a$ and $x=2a$ respectively. The resultant electric potential at $x=a+r$ if ( a << r) is : $( \varepsilon_0$ is the permittivity of free space)

asked Oct 29, 2013 by meena.p

1 answer

The bob of simple pendulum is hanging vertically down from a fixed identical bob by means of a string of length l. If both bobs are charged with a charge q each , time period of the pendulum is : (ignore the radii of the bobs)

asked Oct 29, 2013 by meena.p

1 answer

Two short managers AB and CD are in the X-Y plane and are parallel to X-axis and coordinate of their centers respectively are (0,2) and (2,0). Line joining the north- south poles of CD is opposite to that of AB and lies along the positive X-axis. The resultant field induction due to AB and CD at a point P(2,2) is $100 \times 10^{-7}\;T$. When the poles of the magnet CD are reversed, the resultant field induction is $50 \times 10^{-7}T$. The value of magnetic moments of AB and CD (in $AM^2$) are :

asked Oct 29, 2013 by meena.p

1 answer

The effect due to uniform magnetic field on a freely suspended magnetic needle is as follows :

asked Oct 29, 2013 by meena.p

1 answer

$3.92g$ of ferrous ammonium sulphate crystals are dissolved in 100ml of water.20ml of this solution requires 18ml of potassium permanganate during titration for complete oxidation .The weight of $KMnO_4$ present in one litre of the solution is

asked Oct 29, 2013 by sreemathi.v

1 answer

In Young's double slit experiment, first slit has width four of the second slit. the ratio of the maximum intensity to the minimum intensity in the interference fringe system is :

asked Oct 29, 2013 by meena.p

1 answer

Match the appropriate pairs from List I and List II

asked Oct 29, 2013 by meena.p

1 answer

$8g$ of sulphur are burnt to form $SO_2$,which is oxidized by $Cl_2$.The solution is treated with $BaC_2$ solution.The amount of $BaSO_4$ percipitated is

asked Oct 29, 2013 by sreemathi.v

1 answer

Consider the decomposition reaction of nitroglycerine $4C_3H_5N_3O_9\rightarrow 6N_2+12CO_2+10H_2O+O_2$. If $200g$ nitroglycerine gives 6.55g $O_2$, then percent yield of the reaction is

asked Oct 29, 2013 by sreemathi.v

1 answer

Dispersive power depends on the following :

asked Oct 29, 2013 by meena.p

1 answer

The two surfaces of a biconvex lens has same radii of curvatures. This lens is made of glass of refractive index 1.5 has a focal length 10 cm in air. The lens is cut into two equal halves along a plane perpendicular to its principal axis to yield two plano-convex lenses. The two pieces are glued such that the convex lenses. The two pieces are glued such that the convex surface touch each other. If this combination lens is immersed in water(refractive index=4/3), its focal length (in cm) is :

asked Oct 29, 2013 by meena.p

1 answer

$100\;mL$ of a mixture of $NaOH$ and $Na_2SO_4$ is neutralized by $10\;mL$ of $0.5\;M$ $H_2SO_4$. Hence $NaOH$ in $100\;mL$ solution is

asked Oct 29, 2013 by sreemathi.v

1 answer

An observer is standing 500 m away from a vertical hill, a police van sounding a siren of frequency 1000 Hz moves towards the hill with a uniform speed. If the frequency of the sound heard directly from the siren is 970 Hz. the frequency of the sound heard after reflection from the hill (in Hz) is about, (velocity of sound =$330\;ms^{-1}$):

asked Oct 29, 2013 by meena.p

1 answer

Volume of 2m HCl required to neutralize the solution containing 1 mole of $NH_4Cl$ and $1$ mole of NaOH is

asked Oct 29, 2013 by sreemathi.v

1 answer

Two string A and b of lengths, $L_a=80\;cm$ and $L_B=x\;cm$ respectively are used separately in a sonometer. The ratio of their densities $(d_A/d_B)$ is $0.81$ The diameter of B is one -half that of A. If the string have the same tension and fundamental frequency the value of x is :

asked Oct 29, 2013 by meena.p

1 answer

Two solid spheres A and B made of the same material have radii $r_A$ and $r_B$ respectively. Both the sphere are cooled from the same temperature under the conditions valid for Newton's law of cooling. The ratio of the rate of change of temperature of A and B is :

asked Oct 29, 2013 by meena.p

1 answer

The cyclic process ABCD is shown below in the given P.V diagram. In the following answers the one that represents the same process as in the P-V diagram

asked Oct 29, 2013 by meena.p

1 answer

Mole fraction of $I_2$ in $C_6H_6$ is 0.2.The molality of $I_2$ in $C_6H_6$ is

asked Oct 29, 2013 by sreemathi.v

1 answer

A given mass of a gas is compressed isothermally until its pressure is doubled. It is then allowed to expand adiabatically until its original volume is restored and its pressure is then found to be 0.75 of its initial pressure. The ratio of the specific heats of the gas is approximately :

asked Oct 29, 2013 by meena.p

1 answer

The temperature of a thin uniform circular disc, of one meter diameter is increased by $10^{\circ}C$. The percentage increase in moment of inertia of the disc about an axis passing through its center and perpendicular to the circular face: (linear coefficient of expansion $=11 \times 10^{-6}/^{\circ}C)$

asked Oct 29, 2013 by meena.p

1 answer

The mole fraction of the solute in one molar aqueous solution is

asked Oct 29, 2013 by sreemathi.v

1 answer

Two block of masses 1 kg and 2 kg are connected by a metal wire going over a smooth in figure. The breaking stress of the metal is $2 \times 10^{9} \;N/m^2$. What should be the minimum radius of the wire used if it is not to break? Take $g=10\;ms^2$

asked Oct 29, 2013 by meena.p

1 answer

3.0mole NaOH solution has a density of 1.110g/ml.The molarity of the solution is

asked Oct 29, 2013 by sreemathi.v

1 answer

Molarity of $H_2SO_4$(density 1.8g/ml) is 18m.The molality of this $H_2SO_4$ is

asked Oct 29, 2013 by sreemathi.v

1 answer

An air bubble of radius 1 cm rises from the bottom portion through a liquid of density $1.5 g/cc$ at a constant speed of $0.250 \;cm^{-1}$.If the density of air is neglected, the coefficient of viscosity of the liquid is approximately, (In pas):

asked Oct 29, 2013 by meena.p

1 answer

Two soap bubbles combine to form a single bubble. In this process, the change in volume and surface area are respectively V and A. If P is the atmospheric pressure, and T is the surface tension of the soap solution, the following relation is true.

asked Oct 29, 2013 by meena.p

1 answer

If $30ml$ of $H_2$ and $20ml$ of $O_2$ react to form water,what is left at the end of the reaction

asked Oct 29, 2013 by sreemathi.v

1 answer

Assertion (a) : Ductile metals are used to prepare thin wires. Reason (R) : In the stress - strain curve of ductile metals, the length between the points representing elastic limit and breaking point is very small.

asked Oct 29, 2013 by meena.p

1 answer

The dehydration yield of cyclohexanol to cyclohexene is 75%.What would be the yield if 100g of cyclohexanol is dehydrated?

asked Oct 29, 2013 by sreemathi.v

1 answer

The no of moles of $KMnO_4$ that will be needed to react with one mole of sulphite ion in acidic solution

asked Oct 29, 2013 by sreemathi.v

1 answer

A solution is 0.5m in $MgSO_4$,0.1M $Alcl_3$ and 0.2M in $(NH_4)_2SO_4.$The total ionic strength is

asked Oct 29, 2013 by sreemathi.v

1 answer

The total ionic strength (total molarity of all ions) Containing 0.1m of $CuSO_4$ and 0.1m of $Al_2(SO_4)_3$ is

asked Oct 29, 2013 by sreemathi.v

1 answer

The molality of 1 litre solution with $X\%$ by weight $H_2SO_4$ is equal to 9.The weight of the solvent present in the solution is 910g.The value of $X$ :

asked Oct 29, 2013 by sreemathi.v

1 answer

To the free end of spring hanging from a rigid support, a block of mass m is hung and slowly allowed to come to its equilibrium position. Then stretching in the spring is d. If the same block is attached to the same spring and allowed to fall suddenly, the amount of stretching is : (force constant , k)

asked Oct 28, 2013 by meena.p

1 answer

Assertion (a) : A particle of mass m dropped into a hole made along the diameter of the earth from one end to another and possess simple harmonic mention. Reason (R) : Gravitational force between any two particles is inversely proportional to the square of the distance between them.

asked Oct 28, 2013 by meena.p

1 answer

Assume the earths orbit around the sun as circular and the distance between their centers as D. Mass of the earth is M and its radius is R. If earth has an angular velocity $\omega _0$ with respect to its center and $\omega$with respect to the center of the sun, the total kinetic energy of earth is :

asked Oct 28, 2013 by meena.p

1 answer

A uniform rod of length 8a and mass 6m lies on a smooth horizontal surface. Two points masses m and 2m moving in the same plane with speed 2v and v respectively strikes the rod perpendicularly at distances a and 2a from the mid point of the rod in the opposite directions and stick to the rod. The angular velocity of the system immediately after the collision is :

asked Oct 28, 2013 by meena.p

1 answer

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