Recent questions tagged jeemain

The sides of a $\Delta$le are three consecutive natural numbers and its largest angle is twice the smallest one.Determine the sides of the triangle

asked Oct 21, 2013 by sreemathi.v

1 answer

Which one of the following is a correct set?

asked Oct 21, 2013 by meena.p

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The bond length of HCl molecules is $1.275\;A^{\circ}$ and its dipole moment is $1.03\;D$. The ionic character of the molecule (in percent) (charge of the electron $=4.8 \times 10^{-10}\;e.s.u)$ is

asked Oct 21, 2013 by meena.p

1 answer

The atomic numbers of elements $\underline {A}, \underline {B}, \underline {C}$ and $\underline {D}$ are $z-1,z,z+=1$ and $z+2$ respectively. If '$\underline {B}$' is a noble gas, choose the correct answers from the following statements :

asked Oct 21, 2013 by meena.p

1 answer

If the mass defect of , $B^{11}$ is $0.081\;amu,$ its average binding energy (in Mev) is

asked Oct 21, 2013 by meena.p

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The velocities of two particles $\underline {A}$ and $\underline {B}$ are $00.05$ and $0.02\;ms^{-1}$ respectively. The mass of $\underline {B}$ is five times the mass of $\underline {A}$. The ratio of their de Broglie's wavelength is

asked Oct 21, 2013 by meena.p

1 answer

An electronic transition in hydrogen atom results, in the formation of $H_{\alpha}$ line of hydrogen in Lyman series, the energies associated with the electron in each of the orbits involved in the transition (in $kCal mol^{-1}$) are

asked Oct 21, 2013 by meena.p

1 answer

The angles $A,B$ and $C$ of a triangle ABC are in arithmetic progression.If $2b^2=3C^2$ determine the angle A

asked Oct 21, 2013 by sreemathi.v

1 answer

Let $a,b,c$ be positive real numbers .Let $\theta=\tan^{-1}\sqrt{\large\frac{a(a+b+c)}{bc}}+$$\tan^{-1}\sqrt{\large\frac{b(a+b+c)}{ca}}$$+\tan^{-1}\sqrt{\large\frac{c(a+b+c)}{ab}}$.Then $\tan\theta$

asked Oct 21, 2013 by sreemathi.v

1 answer

The value of the expression $\large\frac{\sin^3x}{1+\cos x}+\frac{\cos^3x}{1-\sin x}$ is

asked Oct 21, 2013 by sreemathi.v

1 answer

If $A+B+C=\pi$ then $\cos^2A+\cos^2B+\cos^2C$ is equal to

asked Oct 21, 2013 by sreemathi.v

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Which of the following statement is not correct when a junction diode is in forward bias?

asked Oct 20, 2013 by meena.p

1 answer

$F_{pp}.F_{nn}$ and $F_{np}$ are the nuclear forces between proton- proton, neutron-neutron and neutron proton respectively . Then relation between them is

asked Oct 20, 2013 by meena.p

1 answer

An X-ray tube produce a continuous spectrum of radiation with its shortest wavelength of $45 \times 10^{-2} A^{\circ}$. The maximum energy of a photon in the radiation in $eV$ is $(h=6.62 \times 10^{-34} \;J-sec, c= 3 \times 10^8 m/sec)$

asked Oct 20, 2013 by meena.p

1 answer

X-rays of energy 50 KeV and scattered from a carbon target. The scattered rays are deleted at $90^{\circ}$ from the innocent beam. The percentage changes in wavelength approximately $[m_e= 9.0 \times 10^{-31}kg, c= 3 \times 19^8 m/sec]$ is

asked Oct 20, 2013 by meena.p

1 answer

The number of turns in primary and secondary coils of a transformer is 50 and 200. If the current in the primary coil in 4A, then the current in the secondary coil is

asked Oct 20, 2013 by meena.p

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Two concentric coils of 10 turns each are placed in the same plane. Their radii are 20 cm and 40 cm and carry 0.2 and 0.3 amp. current respectively in opposite directions. The magnetic induction (in Tesla) at the center is

asked Oct 20, 2013 by meena.p

1 answer

In galvanometer $5\%$ of the total current in the circuit passes through it. If the resistance of the galvanometer is G the shunt resistance 'S' connected to the galvanometer is

asked Oct 20, 2013 by meena.p

1 answer

The number of lone pairs of electrons on $Xe\: in\: XeF_2, XeF_4\: and \: XeF_6$ are, respectively

asked Oct 20, 2013 by thanvigandhi_1

1 answer

Chlorine reacts with ammonia and gives nitrogen. The ratio of chlorine to ammonia in this reaction is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A conductor has a non-uniform section as shown in the figure. A steady current is flowing through it. Then the drift speed of the electrons

asked Oct 20, 2013 by thanvigandhi_1

1 answer

The thermo emf in lead-iron thermocouple with one junction at $0^{\circ}C$ , is given by $e=1784t-bt^2$ in volts, where $t^{\circ}C$ is the temperature of the other junction. The neutral temperature is $371.7^{\circ}C$. Then the value of b in $V/(^{\circ}C)^2$ is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A long straight wire along the Z-axis carries a current 'I' in the negative Z-direction . The induced magnetic field B at a point having coordinates (x,y) is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

The deflection of the magnetic needle in an tangent galvanometer is $30^{\circ}$ when a current of one ampere flows through it. The deflection of the magnetometer when a current of 4 amp flows through it is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

The X-ray spectrum coming from an X-ray tube

asked Oct 20, 2013 by thanvigandhi_1

1 answer

The de-Broglie wavelength of a free electron with kinetic energy 'E' is $ \lambda$. If the kinetic energy of the electron is doubled, the de-Broglie wavelength is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A radioactive substance has density $ \rho$ , volume V, and decay constant $ \lambda$. If the molecular weight of the substance is M, and Avogadro number is $N_a$ then the radioactivity of the substance after time 't' is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A certain particle has a half life of 60 seconds. The fractions of the particles that will decay at the end of 10 seconds is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

For a transistor to work as an amplifier

asked Oct 20, 2013 by thanvigandhi_1

1 answer

An electrical device which offers a low resistance to the current in one direction but a high resistance to the current in opposite direction is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

If the liquid in a U tube rises to a high level in the limb placed between poles of an electromagnet, then the liquid is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A magnetic dipole is placed under the effect of two magnetic fields inclined at $ 75^{\circ}$ to each other. One of the fields has a magnetic Induction of $ 1.5 \times 10^{-2}T$. The magnet comes to rest at an angle of $30^{\circ}$ with the direction of this field . The magnitude of the other field is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

If the last term in the expansion of $\bigg(2^{\large\frac{1}{3}}-\frac{1}{\sqrt{ 2}}\bigg)^n $ is $\bigg(\large\frac{1}{3^{\large\frac{5}{3}}}\bigg)^{log_38}$, then the $5^{th} $ term from the beginning is ?

asked Oct 20, 2013 by rvidyagovindarajan_1

1 answer

If the sum of the coefficients of $1^{st},\:2^{nd}$ and $3^{rd}$ terms in the expansion of $(x^2+\large\frac{1}{x})$$^n $ is $46$, then the coefficient of the term independent of $x$ = ?

asked Oct 20, 2013 by rvidyagovindarajan_1

1 answer

A copper constantan thermocouple produces an e.m.f of $40\;\mu V$ per $^{\circ}C$. The smallest temperature difference that can be measured with this thermocouple is $42.5 ^{\circ}C$, When a galvanometer capable of detecting as low as $10^{-6}\;amp$ is employed. The resistances of that galvanometer is

asked Oct 20, 2013 by meena.p

1 answer

The objective lens of an optical Instrument is an achromat combination with a focal length of 90 cm. The two lenses possess dispersive powers 0.024 and 0.036 respectively and are in contact with each other. Then their focal lengths are

asked Oct 20, 2013 by thanvigandhi_1

1 answer

When a battery connected across a resistor of $416 \Omega$, the voltage across the resistor is 12 V. When the same battery is connected across a resistor of $10 \Omega$, Voltage across it is 11V. The internal resistance of the battery in Ohms is

asked Oct 20, 2013 by meena.p

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Image of an object at infinity is formed by a convex lens of focal length 30 cm such that the size of the image is 2 cm. If a concave lens of focal length 20 cm is placed in between the convex lens and the image, at a distance 26 cm, from the convex lens size of the new image is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A current of 2 A. flows in an electric circuit as shown in figure. The potential difference $(V_R-V_s)$, in volts ($V_R$ and $V_s$ are potentials at R and S respectively ) is

asked Oct 20, 2013 by meena.p

1 answer

If 'f' is focal length of lens in Ramsden's eye peice, crossed wires are placed at

asked Oct 20, 2013 by thanvigandhi_1

1 answer

Two charges $+q$ and $-q$ are kept apart. Then at any point on the right bisector of line joining the two charges.

asked Oct 20, 2013 by meena.p

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A progressive wave of frequency 500 Hz is travelling with a speed of 330 m/s in air. The distance between the two points which have a phase difference of $30^{\circ}$ is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

A change of $1 \mu C$ is divided into two parts such that their charges are in the ratio of $2:3$. These two charges are kept at a distance 1 m apart in vacuum. Then, the electric force between them (in Newtons) is

asked Oct 20, 2013 by meena.p

1 answer

The successive resonance frequencies in an open organ pipe are 1944 Hz and 2600 Hz. The length of the pipe if the speed of sound in air is 328 m/sec is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

The magnetised wire of moment 'M' and length 'l' is bent in the form of semicircle of rdius 'r'. then its magnetic moment is

asked Oct 20, 2013 by meena.p

1 answer

The room temperature is $ + 20^{\circ}C$ when outside temperature is $- 20^{\circ}C$. Room temperature is $ + 10^{\circ}C$ when outside temperature is $ - 40^{\circ}C$. The temperature of the radiator heating the room is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

Assertion (A) : The air pressure in the car tyre increases during driving. Reasons (R) : Temperature of air in the tyre increases due to friction of tyre with road. Increase in temperature results in an increase in pressure according to Charle's law .

asked Oct 20, 2013 by thanvigandhi_1

1 answer

With a standard rectangular bar magnet the time period of a vibration magnetometer is 4 seconds. The bar magnet is cut parallel to its length into four equal pieces. The time period of vibration magnetometer when one piece is used (in seconds) (bar magnet breadth is small ) is

asked Oct 20, 2013 by meena.p

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Equal masses of three liquids, A, B and C have temperatures $ 10^{\circ}C, 25^{\circ}C \: and \: 40^{\circ}C$ respectively. If A and B are mixed, the mixtures has a temperature of $15^{\circ}C$. If B and C are mixed, the mixtures has a temperature of $30^{\circ}C$. If A and C are mixed, the temperature of the mixture is

asked Oct 20, 2013 by thanvigandhi_1

1 answer

Two roads of lengths $L_1 \: and \: L_2$ are welded together to make a composite rod of length $(L_1 + L_2)$. If the coefficient of linear expansion of the materials of the rods are $( \alpha_1 \: and \: \alpha_2)$ respectively, the effective coefficient of linear expansion of the composite rod is

asked Oct 20, 2013 by thanvigandhi_1

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