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Let the sum of the first three terms of an A.P. be 39 and the sum of its last four terms be 178. If the first term of this A.P. is 10, then the median of the A.P. is :

asked Sep 29, 2015 by meena.p

1 answer

The number of ways of selecting 15 teams from 15 men and 15 women, such that each team consists of a man and a woman, is :

asked Sep 29, 2015 by meena.p

1 answer

If $A=\begin{bmatrix} 0 & -1 \\ 1 & 0 \end{bmatrix}$ then which one of the following statements is not correct ?

asked Sep 29, 2015 by meena.p

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The least value of the product xyz for which the determinant $\begin{bmatrix}x & 1 & 1\\1 & y & 1\\1 & 1 & z\end{bmatrix}$ is non-negative , is :

asked Sep 29, 2015 by meena.p

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If $2+3i$ is one of the roots of the equation $2x^3-9x2+kx-13=0,$ k \in R$, then the real root of this equation

asked Sep 29, 2015 by meena.p

1 answer

The largest value of r for which the region represented by the set $\{\omega \in C/| \omega -4-i| \geq r \}$ is contained in the region represented by the set $\{z \in C/|Z-1| \geq | z+i| \}$ is equal to :

asked Sep 29, 2015 by meena.p

0 answers

In a certain town, $25\%$ of the families own a phone and $15 \%$ own a car ; $65\%$ families own neither a phone nor a car and $2,000$ families own both a car and a phone.Consider the following three statements : (a) $5\%$ families own both a car and a phone. (b) $35\%$ families own either a car or a phone. (c) $40,000$ families live in the town. Then,

asked Sep 29, 2015 by meena.p

1 answer

The cation that will not be precipitated by $H_2S$ in the presence of dil $HCl$ is :

asked Sep 29, 2015 by meena.p

1 answer

Refer the following diagram :

asked Sep 29, 2015 by meena.p

1 answer

Match the polymers in column-A with their main uses in column-B and choose the correct answer :

asked Sep 29, 2015 by meena.p

1 answer

Arrange the following amines in the order of increasing basicity.

asked Sep 29, 2015 by meena.p

1 answer

In the presence of a small amount of phosphorous, aliphatic carboxylic acids react with chlorine or bromine to yield a compound in which a - hydrogen has been replaced by halogen. This reaction is known as :

asked Sep 29, 2015 by meena.p

1 answer

A compound A with molecular formula $C_{10}H_{13}Cl$ gives a white precipitate on adding silver nitrate solution. A on reacting with alcoholic $KOH$ gives compound $B$ as the main product. B on ozonolysis gives $C$ and $D$. $ C$ gives Cannizaro reaction but not aldol condensation. $D$ gives aldol condensation but not Cannizaro reaction. $A$ is :

asked Sep 29, 2015 by meena.p

1 answer

In the equation below, value of A is

asked Sep 29, 2015 by meena.p

1 answer

The optically inactive compound from the following is :

asked Sep 29, 2015 by meena.p

1 answer

$1.4\; g$ of an organic compound was digested according to Kjeldahls method and the ammonia evolved was absorbed in $60\; mL$ of $M/10\; H_2SO_4$ solution. The excess sulphuric acid required $20\;mL$ of $M/10\;NaOH$ solution for neutralization. The percentage of nitrogen in the compound is :

asked Sep 28, 2015 by meena.p

1 answer

Photochemical smog consists of excessive amount of X, in addition to aldehydes, ketones, peroxy acetyl nitrile (PAN), and so forth. X is :

asked Sep 28, 2015 by meena.p

1 answer

The correct statement on the isomerism associated with the following complex ions,$ (a) [Ni(H_2O)_5NH_3]^{2+},\\ (b) [Ni(H_2O)_4(NH_3)_2]^{2+} \;and\\ (c) [Ni(H_2O)_3(NH_3)_3]^{2+}\; is :$

asked Sep 28, 2015 by meena.p

1 answer

Which molecule/ion among the following cannot act as a ligand in complex compounds ?

asked Sep 28, 2015 by meena.p

1 answer

Which molecule/ion among the following cannot act as a ligand in complex compounds ?

asked Sep 28, 2015 by meena.p

0 answers

An aqueous solution of a salt X turns blood red on treatment with $SCN^{-}$ and blue on treatment with $K_4[Fe(CN)_6]$. $X$ also gives a positive chromyl chloride test. The salt X is :

asked Sep 28, 2015 by meena.p

1 answer

The geometry of $XeOF_4$ by $VSEPR$ theory is

asked Sep 28, 2015 by meena.p

1 answer

The least number of oxyacids are formed by :

asked Sep 28, 2015 by meena.p

1 answer

The correct order of thermal stability of hydroxides is :

asked Sep 28, 2015 by meena.p

1 answer

Permanent hardness in water cannot be cured by :

asked Sep 28, 2015 by meena.p

1 answer

In the isolation of metals, calcination process usually results in :

asked Sep 28, 2015 by meena.p

1 answer

In the long form of the periodic table, the valence shell electronic configuration of $5s^2, 5p^4$ corresponds to the element present in :

asked Sep 28, 2015 by meena.p

1 answer

The following statements relate to the adsorption of gases on a solid surface. Identify the incorrect statement among them :

asked Sep 28, 2015 by meena.p

1 answer

The reaction $2N_2O_5(g) \to 4NO_2(g) +O_2(g)$ follows first order kinetics . The pressure of a vessel containing only $N_2O_5$ was found to increase from $50 \;mm$ Hg to $87.5\;mm$ Hg in 30 min. The pressure exerted by the gas after 60 min will be (Assume temperature remains constant ) :

asked Sep 28, 2015 by meena.p

1 answer

A variable, opposite external potential $(E_{ext})$ is applied to the cell $Zn|Zn^{2+} (1 M) || Cu^{2+} (1 M) | Cu,$ of potential $1.1\; V$. When $E_{ext} < 1.1 V$ and $E_{ext} > 1.1 V,$ respectively electrons flow from :

asked Sep 28, 2015 by meena.p

1 answer

Gaseous $N_2O_4$ dissociate into gaseous $NO_2$ according to the reaction $N_2O_4(g) \to 2NO_2(g)$. At 300 K and 1 atm pressure , the degree of dissociation of $N_2O_4$ is $0.2$. If one mole of $N_2O_4$ gas is contained in a vessel, then the density of the equilibrium mixture is :

asked Sep 28, 2015 by meena.p

1 answer

A solution at $20^{\circ}C$ is composed of $1.5\;mol$ of benzene and $3.5\; mol$ of toluene. If the vapour pressure of pure benzene and pure toluene at this temperature are $74.7$ torr and $22.3$ torr, respectively, then the total vapour pressure of the solution and the benzene mole fraction in equilibrium with it will be, respectively :

asked Sep 28, 2015 by meena.p

1 answer

The heat of atomization of methane and ethane are $360 \;kJ/mol$ and $620 kJ/mol,$ respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number=6.02 \times 10^{23},h= 6.62 \times 10^{-34}\;Js)$: h56.62310234 J s) :

asked Sep 28, 2015 by meena.p

1 answer

After understanding the assertion and reason, choose the correct option. Assertion : In the bonding molecular orbital (MO) of $H_2$, electron density is increased between the nuclei. Reason : The bonding $MO$ is which shows destructive interference of the combining electron waves.

asked Sep 28, 2015 by meena.p

1 answer

If the principal quantum number $n=6$, the correct sequence of filling of electrons will be :

asked Sep 28, 2015 by meena.p

1 answer

Which of the following is not an assumption of the kinetic theory of gases ?

asked Sep 28, 2015 by meena.p

1 answer

A sample of a hydrate of barium chloride weighing $61\;g$ was heated until all the water of hydration is removed . The dried sample weighted $52\;g$ The formula of the hydrated salt is : (atomic mass, Ba=137 amu, Cl=35.5 amu)

asked Sep 28, 2015 by meena.p

1 answer

Diameter of a steel ball is measured using a Vernier callipers which has divisions of $0.1\;cm$ on its main scale (MS) and $10$ divisions of its vernier scale (VS) match $9$ divisions on the main scale. Three such measurements for a ball are given as : If the zero error is 20.03 cm, then mean corrected diameter is :

asked Sep 28, 2015 by meena.p

1 answer

In an unbiased n-p junction electrons diffuse from n - region to p - region because :

asked Sep 28, 2015 by meena.p

1 answer

If one were to apply Bohr model to a particle of mass m and charge q moving in a plane under the influence of a magnetic field B, the energy of the charged particle in the nth level will be :

asked Sep 28, 2015 by meena.p

2 answers

de-Broglie wavelength of an electron accelerated by a voltage of $50\; V$ is close to $(|e|=1.6 \times 10^{-19}\; C, m_e=9.1 \times 10^{-31}\; kg,h=6.6 \times 10^{-34}\;Js)$ :

asked Sep 25, 2015 by meena.p

1 answer

A telescope has an objective lens of focal length $150\;cm$ and an eyepiece of focal length $5\;cm$. If a $50\; m$ tall tower at a distance of 1 km is observed through this telescope in normal setting, the angle formed by the image of the tower is $\theta$, then $\theta$ is close to :

asked Sep 25, 2015 by meena.p

1 answer

A parallel beam of electrons travelling in x-direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum $P_y$ in the y-direction then for a majority of electrons passing through the slit (h is Plancks constant) :

asked Sep 25, 2015 by meena.p

1 answer

You are asked to design a shaving mirror assuming that a person keeps it $10\; cm$ from his face and views the magnified image of the face at the closest comfortable distance of $25\; cm$. The radius of curvature of the mirror would then be :

asked Sep 25, 2015 by meena.p

1 answer

An electromagnetic wave travelling in the x-direction has frequency of $2 \times 10^{14}\; Hz$ and electric field amplitude of $27 \;Vm^{-1}$. From the options given below, which one describes the magnetic field for this wave ?

asked Sep 25, 2015 by meena.p

1 answer

In the circuits (a) and (b) switches $S_1$ and $S_2$ are closed at $t=0$ and are kept closed for a long time. The variation of currents in the two circuits for $t \geq 0$ are roughly shown by (figures are schematic and not drawn to scale) :

asked Sep 25, 2015 by meena.p

1 answer

When current in a coil change from $5\;A$ to $2\;A$ in $0.1\;s$, an average voltage of $50\;V$ is produced . The self- inductance of the coil is :

asked Sep 25, 2015 by meena.p

1 answer

A 25 cm long solenoid has radius 2 cm and 500 total number of turns. It carries a current of 15 A. If it is equivalent to a magnet of the same size and magnetization $\overrightarrow{M}$ (magnetic moment /volume), then $|\overrightarrow{M}| $ is :

asked Sep 25, 2015 by meena.p

1 answer

A proton (mass m) accelerated by a potential difference V flies through a uniform transverse magnetic field B. The field occupies a region of space by width d. If $\alpha$ be the angle of deviation of proton from initial direction of motion (see figure), the value of $\sin \alpha$ will be :

asked Sep 25, 2015 by meena.p

1 answer

A $10\;V$ battery with internal resistance $1V$ and a $15V$ battery with internal resistance $0.6V$ are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to :

asked Sep 25, 2015 by meena.p

1 answer

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