Recent questions tagged jeemain

For the electro chemical cell $ M | M^{+} || X^{-} | X, E^{0}(M^{+} | M)=0.44\;V$ and $E^{0} (X | X ^{-})=0.33\;V.$ Which one of the following is true for this data?

asked Sep 25, 2013 by meena.p

0 answers

A solution of 10 g of non-volatile binary electrolyte (mol wt=100) in 500 g of water freezes at $-0.74^{\circ}C$. What is the degree of ionisation ? ($k_f$ of water$=1.85\;K \; molality^{-1})$

asked Sep 25, 2013 by meena.p

1 answer

In acidic medium, $100\; ml$ of $0.01\;M\;KMnO_4$ solution oxides $100\;ml$ of $H_2O_2$ solution. The volume of $0.01\;M\;KMnO_4$ required to oxidize the same volume of $H_2O_2$ in alkaline medium in ml. is :

asked Sep 25, 2013 by meena.p

1 answer

Which one of the following statement is not correct?

asked Sep 25, 2013 by meena.p

1 answer

A metal nitride contains $28 \%$ nitrogen by weight. The molecular formula of metal nitride is $M_3N_2$. What is the atomic weight of metal?

asked Sep 24, 2013 by meena.p

1 answer

The sensitivity of a galvanometer is $60$ divisions /Amp. When a shunt is used, its sensitivity become 10 divisions/Amp. If the galvanometer is of resistance $20 \Omega$, the value of shunt used is :

asked Sep 24, 2013 by meena.p

1 answer

A constant voltage of $25\; V$ is applied to a series $L-R$ circuit at $t=0$, by closing a switch. What is the potential difference across the resistor and the inductor at time $t=0$?

asked Sep 24, 2013 by meena.p

1 answer

Match the following and find the correct pairs:

asked Sep 24, 2013 by meena.p

1 answer

$^nC_1$ + $2.^nC_2$ + $3.^nC_3$ + ..... + $n.^nC_n$ = ?

asked Sep 24, 2013 by rvidyagovindarajan_1

1 answer

The thermo e.m of a hypothetical thermocouple varies with the temperature $\theta$ of hot junction as $E= a \theta + b \theta^2$ in volts, where the ratio $a/b$ is $700^{\circ}C$. If the cold junction is kept at $0^{\circ}C,$ then the neutral temperature is :

asked Sep 24, 2013 by meena.p

1 answer

Int he circuit shown below, the ammeter reading is zero. Then the value of the resistance $R$ is :

asked Sep 24, 2013 by meena.p

1 answer

The sum of coefficients of odd powers of $x$ in the expansion $(1+x)^{50}$ is ?

asked Sep 24, 2013 by rvidyagovindarajan_1

1 answer

The electric current i in the circuit shown is :

asked Sep 24, 2013 by meena.p

1 answer

If the sum of odd numbered terms and even numbered terms in the expansion of $(x+a)^n$ are $A,B$, then $(x^2-a^2)^n=?$

asked Sep 24, 2013 by rvidyagovindarajan_1

1 answer

Two identical condenser M and N are connected in series with a battery. The space between the plates of M is completely filled with a dielectric medium of dielectric constant 8 and a copper plate of thickness $\large\frac{d}{2}$ is introduced between the plates of N. (d is the distance between the plates). Then potential differences across M and N are, respectively , in the ratio:

asked Sep 24, 2013 by meena.p

1 answer

The no. of terms in the expansion $(x+y+z)^{10}$ is ?

asked Sep 24, 2013 by rvidyagovindarajan_1

1 answer

A fully charged capacitor has a capacitance $'C'$. It is discharged through a small coil resistance wire, embedded in a block of specific heat $'s'$ and mass $'m'$ under thermally isolated conditions. If the temperature of the block is raised by $'\Delta T$, the potential difference $V$ across the capacitor initially is :

asked Sep 24, 2013 by meena.p

1 answer

Some physical quantities are given in the List I and the related units are given in the List II.Match the correct pairs in the list:

asked Sep 24, 2013 by meena.p

1 answer

If the coefficient of $(2r+4)^{th}$ and $(r-2)^{th}$ terms in the expansion of $(1+x)^{18} $ are equal, then $r=?$

asked Sep 24, 2013 by rvidyagovindarajan_1

1 answer

If a bar magnet of pole strength $m$ and magnetic moment M is cut equally 5 times parallel to its axis and again 3 times perpendicular to its axis, then the pole strength and magnetic moment of each piece are respectively:

asked Sep 24, 2013 by meena.p

1 answer

In the Young's double slit experiment, the resultant intensity at a point on the screen is $75 \%$ of the maximum intensity of the bright fringe. Then the phase difference between the two interfering rays at that point is :

asked Sep 24, 2013 by meena.p

1 answer

A ray of light refracts from medium 1 into a thin layer of medium 2, crosses the layer and is incident at the critical angle on the interface between the medium 2 and 3 as shown in figure. If the angle of incidence of ray is $\theta$, the value of $\theta$ is :

asked Sep 24, 2013 by meena.p

3 answers

Which of the following statement are $true$ in the context of a Compound Microscope?

asked Sep 24, 2013 by meena.p

1 answer

The focal length of a lens of dispersive power $0.45$ which should be placed in contact with a convex lens of focal length $84\;cm$ and dispersive power $0.21$ to make the achromatic combination from the two lenses, in cm is :

asked Sep 24, 2013 by meena.p

2 answers

Two uniform stretched string A and B, made of steel , are vibrating under the same tension. If the first overtone of A is equal to the second overtone of B and if the radius of A is twice that of B, the ratio of the lengths of the strings is :

asked Sep 24, 2013 by meena.p

1 answer

The wavelengths of two sound notes in air are $\large\frac{40}{195}\;$$m$ and $\large\frac{40}{193}\;$$m$. Each note produces 9 beats per second separately with a third note of fixed frequency. The velocity of sound in air in m/s is:

asked Sep 24, 2013 by meena.p

1 answer

Two slabs A and B of different materials but of the same thickness are joined and to end to form a composite slab. The thermal conductivities of A and B are $'k_1'$ and $'k_2$ respectively. A steady temperature distance of $12^{\circ}$ is maintained across the composite slab. If $k_1=\large\frac{k_2}{2}$, the temperature difference across slab A is

asked Sep 24, 2013 by meena.p

1 answer

During an adiabatic process, the pressure of a gas is proportional to the cube of its temperature. The value of $C_p/C_v$ for that gas is :

asked Sep 24, 2013 by meena.p

1 answer

A reversible engine converts one-sixth of the heat supplied into work. When the temperature of the sink is reduced by $62^{\circ}C$, the efficiency of the engine is doubled. The temperatures of the source and skin are:

asked Sep 24, 2013 by meena.p

1 answer

An insulated cylindrical vessel filled with an insulated piston of negligible weight and negligible thickness at the mid point of the vessel. The cylinder contains a gas at $0^{\circ}C$. When the gas is heated to $100^{\circ}$, the piston moves through a length of $5 \;cm$. Length of the cylindrical vessel is cm is :

asked Sep 24, 2013 by meena.p

1 answer

A non-conducting body floats in a liquid at $20^{\circ}C$ with $\large\frac{2}{3}$ of its volume immersed in the liquid. When liquid temperature is increased to $100^{\circ}C,\large\frac{3}{4}$ of body's volume is immersed in the liquid . Then the coefficient of real expansion of the liquid is (neglecting the expansion of the liquid):

asked Sep 24, 2013 by meena.p

1 answer

A large open tank has two holes in the wall. One is a square hole of side $'L'$ at a depth $'y'$ from the top and the other is a circular hole of radius R at a depth $'4y'$ from the top. When the tank is completely filled with water, the quantities of water flowing out per second from the two holes are the same. Then value of R is :

asked Sep 24, 2013 by meena.p

1 answer

If two soap bubbles of different radii are connected by a tube, then :

asked Sep 24, 2013 by meena.p

1 answer

Two blocks of masses $1\;kg$ and $2\;kg$ are connected by are connected by a metal wire going over a smooth pulley. The breaking stress of metal is $\large\frac{40}{3 \pi}$$\times 10^6\;Nm^{-2}$.What should be the minimum radius of wire used if it should not break? $(g=10\;m/s^{-2})$

asked Sep 24, 2013 by meena.p

2 answers

A simple harmonic oscillator consists of a particle of mass $'m'$ and an ideal spring with spring constant $'k'$. The particle oscillates with a time period 'T'. The spring is cut into two equal parts. If one part oscillates with the same particle , the time period will be :

asked Sep 24, 2013 by meena.p

1 answer

$\mathbf{Assertion\; (A)}$: An astronaut inside a massive spaceship orbiting around the earth will experience a finite but small gravitational force.$\mathbf{Reason\;(R):}$ The centripetal force necessary to keep the spaceship in orbit around the earth is provided by the gravitational force between the earth and the spaceship.

asked Sep 24, 2013 by meena.p

1 answer

A thin hollow sphere of mass $'m'$ is completely filled with a liquid of mass $'m'$. When the Sphere rolls with a velocity $'c'$, kinetic energy of the system is (neglect friction):

asked Sep 24, 2013 by meena.p

1 answer

Two uniform circular discs having the same mass and the same thickness but different radii are made from different materials. The disc with the smaller rotational inertia is:

asked Sep 24, 2013 by meena.p

1 answer

A uniform chain of length $L$ is lying on the horizontal table . If the coefficient of friction between the chain and the table top is $\mu'$ , what is the maximum length of the chain that can hang over the edge of the table without disturbing the rest of the chain on the table?

asked Sep 24, 2013 by meena.p

2 answers

A circular disc of radius $'R'$ is removed from a bigger circular disc of radius $'2R'$ such that the circumference of the disc touch. The center of mass of the new disc is at a distance $'\alpha R'$ from the center of the bigger disc. The value of $\alpha'$ is

asked Sep 24, 2013 by meena.p

1 answer

A ball is let fall from a height $h_0$. It makes n collisions with the earth. After $'n'$ collisions it rebounds with a velocity $;v_n'$ and the ball rises to a height $h_n$ then coefficient of restitution, is given by

asked Sep 24, 2013 by meena.p

1 answer

The maximum tension a rope can withstand is $6\;kg$ wt. The ratio of maximum acceleration with two boys of masses $20\; kg$ can climb up rope at the same time is :

asked Sep 24, 2013 by meena.p

1 answer

$A I N$ pendulum bob is held at an angle $\theta$ from the vertical by a $2\;N$ horizontal force $\overrightarrow {F}$ as shown in figure. The tension in the string supporting the pendulum bob (in Newtons) is

asked Sep 24, 2013 by meena.p

1 answer

If the third term in the expansion of $\bigg(\large\frac{1}{x}$$+ x^{log_{10}x}\bigg)^5$ is 1000, then $x$ = ?

asked Sep 23, 2013 by rvidyagovindarajan_1

1 answer

A police party is moving in a jeep at a constant speed $v$. They saw a theif at a distance x on a motorcycle which is at rest. The moment the police saw the thief, the thief started at constant acceleration $\alpha$. Which of the following relations is true if the police is able to catch the thief?

asked Sep 23, 2013 by meena.p

1 answer

A certain vector in the $xy$ plane has an $x$ component of 4 m and any component of 10 m. It is then rotated in the $xy$ plane so that its $x-$ component is doubled. Then its new y component is (approximately):

asked Sep 23, 2013 by meena.p

1 answer

The dimensional formula of $\large\frac{1}{2}$$\mu_0H^2(\mu_0$- Permeability of free space and H-magnetic field intensity ) is :

asked Sep 23, 2013 by meena.p

0 answers

In a $p-n$ junction diode the thickness of depletion layer is $2 \times 10^{-6}\;m$ and barrier potential is $0.3\;V$. the intensity of the electric field at the junction is :

asked Sep 23, 2013 by meena.p

1 answer

If $200 \;MeV$ of energy is released in the fission of one nucleus of $^{235}_{92} U$, the number of nuclei that must undergo fission to release an energy of $1000\;J$ is :

asked Sep 23, 2013 by meena.p

1 answer

Calculate the wavelength of the $k_{\alpha}$ line for $z=31$ when $a=5 \times 10^{7}\;Hz^{1/2}$ for a characteristic X-ray spectrum.

asked Sep 23, 2013 by meena.p

1 answer

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