An atom X belongs to 4th period of the periodic table and has highest number of unpaired electrons in comparison to the other elements of the period. The atomic number of X is
A 1.0 M solution with respect to each of the metal halides \[A{{X}_{3}},B{{X}_{2}},C{{X}_{3}}\]and \[D{{X}_{2}}\]is electrolysed using platinum electrodes. If \[E{{{}^\circ }_{{{A}^{3+}}/A}}=1.50V,\,E{{{}^\circ }_{{{B}^{2+}}/B}}=0.3V,\,E{{{}^\circ }_{{{C}^{3+}}/C}}=0.74V,\]\[E{{{}^\circ }_{{{D}^{2+}}/D}}=-2.37V.\] The correct sequence in which the various metals are deposited at the cathode is
Arrange hypophosphorous acid \[({{H}_{3}}P{{O}_{2}}),\]phosphorous acid \[({{H}_{3}}P{{O}_{3}})\]and Phosphoric acid \[({{H}_{3}}P{{O}_{4}})\]in the decreasing order of acidic strength
The pure crystalline substance on being heated gradually first forms a turbid liquid at constant temperature and still at higher temperature turbidity completely disappears. The behavior is a characteristic of substance forming.
Consider a 0.1 M solution of two solutes A and B. A behaves as a non-electrolyte while 80% of B dimerises. Which of the following statement is correct regarding these solutions?
A)
The b.pt of A will be less than B
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B)
The osmotic pressure of B will be more than that of A
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C)
The freezing point of solution A will be less than that of B
A metal gives two chlorides A and B. A gives black precipitate with \[N{{H}_{4}}OH\]and B gives white. With KI, B gives a red precipitate soluble in excess of \[KI.\]A and B are respectively
Potassium permanganate acts as an oxidant in neutral, alkaline as well as acidic media. The final products obtained from it in the three conditions are, respectively
An organic compound 'X' on ozonolysis followed by reduction with \[Zn/{{H}_{2}}O\]gives 2 moles of \[H-\overset{\overset{O}{\mathop{|\,\,|}}\,}{\mathop{C}}\,-H\]and \[H-\overset{\overset{O}{\mathop{|\,\,|}}\,}{\mathop{C}}\,-C{{H}_{2}}-\overset{\overset{O}{\mathop{|\,\,|}}\,}{\mathop{C}}\,-H.\] ?X? is
Two elements A & B form compounds having molecular formulae \[A{{B}_{2}}\] and \[A{{B}_{4}}.\]When dissolved in 20.0 g of benzene 1.00 g of \[A{{B}_{2}}\] lowers f.p. by \[2.3{}^\circ C\] whereas 1.00 g of \[A{{B}_{4}}\]lowers f.p. by \[1.3{}^\circ C\]. The molal depression constant for benzene in 1000 g is 5.1. The atomic masses of A and B are
To detect iodine in presence of bromine, the sodium extract is treated with \[NaN{{O}_{2}}+\]glacial acetic acid \[+\text{ }CC{{l}_{4}}.\]Iodine is detected by the appearance of
A)
yellow colour of \[CC{{l}_{4}}\]layer
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B)
purple colour of\[CC{{l}_{4}}\]
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C)
brown colour in the organic layer of\[CC{{l}_{4}}\]
An organic compound A \[({{C}_{4}}{{H}_{10}}O)\]has two enantiomeric forms and on dehydration it gives B (major product) and C (minor product). B and C are treated with HBr/ Peroxide and the compounds so produced were subjected to alkaline hydrolysis then-
A reaction is found to be second order w.r.t. one of the reactants & has rate constant of \[0.5\text{ }mo{{l}^{-1}}\text{ }d{{m}^{3}}\text{ }{{\min }^{-1}}.\]If initial concentration is \[0.2\text{ }mol\text{ }d{{m}^{-3}}\]then \[{{t}_{1/2}}\]of reaction is
Concentration of \[N{{H}_{4}}Cl\]and \[N{{H}_{4}}OH\]in a buffer solution is in the ratio of 1 : 1, \[{{K}_{b}}\] for \[N{{H}_{4}}OH\]is \[{{10}^{-10}}.\]The pH of the buffer is
The standard reduction potential of \[L{{i}^{+}}/Li,B{{a}^{2+}}/Ba,N{{a}^{+}}/Na\]and \[M{{g}^{+}}/Mg\]are -3.05, -2.73, -2.71 and -2.37 volts respectively. Which one of the following is strongest oxidising agent?
A bullet comes out of a gun with a velocity of 600 m/s. At what height from the target should the gun be aimed in order to hit the target situated at a distance of 200 m from the gun?
A gramophone record is revolving with an angular velocity \[\omega .\] A coin is placed at a distance r from the center of the record. The static coefficient of friction is \[\mu .\]The coin will revolve with the record if
A pendulum consists of a wooden bob of mass m and length \['\ell '.\]A bullet of mass \[{{m}_{1}}\]is fired towards the pendulum with a speed \[{{v}_{1}}.\]The bullet emerges out of the bob with a speed\[{{v}_{1}}/3,\]and the bob just completes motion along a vertical circle. Then v, is
A particle of mass m, collides head-on with another stationary particle of mass \[{{m}_{2}}({{m}_{2}}<{{m}_{1}}).\]The collision is perfectly inelastic. The fraction of kinetic energy which is converted into heat in this collision is
A beaker containing a liquid of density \[\rho \] moves up with an acceleration a. The pressure due to the liquid at a depth h below the free surface of the liquid is
A wooden block of volume 1000 cc is suspended from a spring balance. It weighs 12 N in air. It is then held suspended in water with half of it inside water. What would be the reading in spring balance now?
A square wire frame of size L is dropped in a liquid. On taking out, a membrane is formed. If the surface tension of the liquid is T, force acting on the frame will be
Statement-1: Two different gas molecules having same temperature will have the same K.E. Statement -2: KE of gas molecules follows the Boltzmann's law.
A)
Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1.
doneclear
B)
Statement-1 is true, Statement-2 is true; Statement-2 is not a correct explanation for Statement-1.
1/2 mole of helium gas is contained in a container at S.T.P. The heat energy needed to double the pressure of the gas, keeping the volume constant (heat capacity of the gas\[=3J{{g}^{-1}}{{K}^{-1}})\]is
A sphere, a cube and a thin circular plate all made of the same material and having the same mass, are initially heated to a temperature of \[200{}^\circ C\]. Which of these objects will cool slowest when left in air at room temperature?
A system changes from the state \[({{P}_{1}},\,\,\,{{V}_{1}})\] to \[({{P}_{2}},\,\,\,{{V}_{2}})\]as shown in the figure below. What is the work done by the system?
A cylinder of radius R made of a material of thermal conductivity \[{{K}_{1}}\] is surrounded by a cylindrical shell of inner radius R & outer radius 2R made of a material of thermal conductivity \[{{K}_{2}}.\]The two ends of the combined system are maintained at two different temperatures. There is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system is
Figure shows a closed surface which intersects a conducting sphere. If a positive charge is placed at the point P, the flux of the electric field through the closed surface
Parallel plate capacitors \[{{C}_{1}}\]& \[{{C}_{2}}\]have the same area with \[{{C}_{1}}\]having half the plate separation as \[{{C}_{2}}.\,\,{{C}_{1}}\] is inserted wholly inside \[{{C}_{2}}\] as shown with their plates joined as shown. The capacitance across terminals AB will be
In the figure battery B supplies 12 V. Take \[{{C}_{1}}=1\,\mu F,\,\,{{C}_{2}}=2\,\mu F,\,\,{{C}_{3}}=3\,\mu F,\,{{C}_{4}}=\,4\mu F.\] Charge on capacitor g) when only\[{{C}_{1}}\]is closed is
The instantaneous values of current and voltage in an A.C. circuit are \[I=4\sin \,\,\omega t\]and \[E=100\cos \,\left( \omega t+\frac{\pi }{3} \right)\]respectively. The phase difference between voltage and current is
An alternating voltage E(in volt) \[200\sqrt{2}\]sin 100 t is connected to one microfarad capacitor through an A.C. ammeter. The reading of the ammeter shall be
A proton, a deutron and an \[\alpha \]particle accelerated through the same potential difference enter a region of uniform magnetic field, moving at right angles to B. What is the ratio of their K.E.?
A simple pendulum with a bob of mass 'm' oscillates from A to C and back to A such that PB is H. If the acceleration due to gravity is 'g' then the velocity of the bob as it passes through B is p
A ray of light is incident at an angle of \[60{}^\circ \] on one face of a prism of angle \[30{}^\circ \]. The ray emerging out of the prism makes an angle of \[30{}^\circ \] with the incident ray. The emergent ray is
A)
Normal to the face through which it emerges
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B)
Inclined at \[30{}^\circ \] to the face through which it emerges
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C)
Inclined at \[60{}^\circ \] to the face through which it emerges
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D)
Inclined at \[90{}^\circ \] to the normal at face through which it emerges
Statement 1: A current flows in a conductor only when there is an electric field within the conductor. Statement 2: The drift velocity of electron in presence of electric field decreases.
A)
Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1.
doneclear
B)
Statement-1 is true, Statement-2 is true: Statement-2 is not a correct explanation for Statement-1.
Two periodic waves of intensities \[{{I}_{1}}\] and \[{{I}_{2}}\] pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is
A hydrogen-like atom has one electron revolving around a stationary nucleus. The energy required to excite the electron from the second orbit to the third orbit is 47.2 eV. The atomic number of the atom is
In Millikan oil drop experiment, a charged drop of mass \[1.8\times {{10}^{-14}}\text{ }kg\]is stationary between its plates. The distance between its plates is 0.90 cm and potential difference is 2.0 kilovolts. The number of electrons on the drop is
If the function \[f(x)=P{{e}^{2x}}+Q{{e}^{x}}+Rx\]satisfies the conditions \[f(0)=-1,\,\,f'(\log 2)=31\]and\[\int_{0}^{\log \,4}{(f(x)-Rx)dx=\frac{39}{2}},\]then
Statement-1: The area of the ellipse \[2{{x}^{2}}+3{{y}^{2}}=6\] is more than the area of the circle \[{{x}^{2}}+{{y}^{2}}-2x+4y+4=0.\]
Statement-2: If the length of the major axis of an ellipse is more than the diameter of a circle then the area of the ellipse will be more than the area of the circle.
A)
Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1.
doneclear
B)
Statement-1 is true, Statement-2 is true; Statement-2 is not a correct explanation for Statement-1.
Statement-1: The domain of the function\[f(x)=\sqrt{{{\log }_{2}}\sin x}\]is \[(4n+1)\frac{\pi }{2},n\in N.\] Statement-1: Expression under even root should be\[\ge 0\]
A)
Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1.
doneclear
B)
Statement-1 is true, Statement-2 is true; Statement-2 is not a correct explanation for Statement-1.
Two finite sets have m and n elements. The total number of subsets of the first set is 56 more than the total number of subsets of the second set. Then:
If g = {(1, 1), (2, 3), (3, 5), (4, 7)} is a function described by the formula, \[g(x)=\alpha x+\beta \]then what values should be assigned to \[\alpha \] and \[\beta \]?
The roots a and P of the quadratic equation\[p{{x}^{2}}+qx+r=0\]are real and of opposite signs. The roots of \[\alpha {{(x-\beta )}^{2}}+\beta {{(x-\alpha )}^{2}}=0\]
If the slope of the tangent at (x, y) to a curve passing through\[\left( 1,\frac{\pi }{4} \right)\]is given by \[\frac{y}{x}-{{\cos }^{2}}\left( \frac{y}{x} \right),\] then the equation of the curve is
If \[\left| \begin{matrix} a & {{a}^{2}} & 1+{{a}^{3}} \\ b & {{b}^{2}} & 1+{{b}^{3}} \\ c & {{c}^{2}} & 1+{{c}^{3}} \\ \end{matrix} \right|=0\]and the vectors \[\overrightarrow{\text{A}}=(1,\,a,\,{{a}^{2}});\] \[\overrightarrow{\text{B}}=(1,\,b,\,{{b}^{2}});\,\overrightarrow{\text{C}}=\text{(1,}\,\text{c,}\,{{\text{c}}^{2}}\text{)}\]are non-coplanar then the product abc =
A and B are two independent witnesses (i.e. there is no collusion between them) in a case. The probability that A will speak the truth is x and the probability that B will speak the truth is y. A and B agree in a certain statement. The probability that the statement is true is