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The innermost orbit of the hydrogen atom has a diameter 1.06 Å. The diameter of tenth orbit is
A resistance of 40 ohm and an inductance of 95.5 millihenry are connected in series in a 50 cycles/second A.C. circuit. The impedance of this combination is very nearly
An object of mass 10 kg is whirled round a horizontal circle of radius 4 m by a revolving string inclined 30º to the vertical. If the uniform speed of the object is 5 ms⁻^{1, }the tension in the string is
A coil of 40 H inductance is connected in series with a resistance of 8 Ω and the combination is joined to the terminals of a 2 V battery. The timeconstant of the circuit is
For the production of Xrays, the target should be made of
An electric dipole is placed along the Xaxis at the origin O. A point P is at a distance of 20 cm from this origin such that OP makes an angle π/3 with the X axis. If electric field at P makes an angle θ with Xaxis, the value of θ is
Two charged conducting spheres of radii a and b are connected to each other by a wire. The ratio of electric fields at the surface of two spheres is
A lift is moving upward with increasing speed with acceleration 'a'. The apparent weight will be
If the coefficient of friction between the tyres and the road is 0.4, then maximum speed of a car on a roadturn of radius 30 m, will be
Two NOT gates are connected at the two inputs of a NAND gate. This combination will behave like
A long solenoid has a radius a and number of turns per unit length is n. If it carries a current I, then the magnetic field on its axis is directly propotional to
A horizontal pipe line carries water in a streamline flow. At a point along the pipe where crosssectional area is 10 cm^{2}, the velocity of water is 1 ms⁻^{1} and pressure is 2000 Pa. The pressure of water, at another point where crosssectional area is 5 cm^{2}, is (Density of water = 1000 kgm⁻^{3})
A particle has an initial velocity of 3 i ‸ + 4 j ‸ and an acceleration of 0.4 i ‸ + 0.3 j ‸ . Its speed after 10s is
If in a nuclear reactor using U^{235} as fuel, the power output is 4.8 mega watts, the number of fissions per second is:
(energy released per fission of U^{235} = 200 MeV; 1eV = 1.6 x 10 ^{− 19} J)
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A): Air quickly leaking out of a balloon becomes cooler.
Reason(R): The leaking air undergoes adiabatic expansion. Reason(R): The leaking air undergoes adiabatic expansion.
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A):If the string of a descending lift is broken, then it will fall down like a free body.
Reason(R):The acceleration of a free body is always 'g'.
A circular disc is rotating with angular velocity ω. A man sitting at the edge walks towards the centre of disc, then the angular velocity ω
During an adiabatic process, the pressure of a gas is proportional to the cube of its adiabatic temperature. The value of for that gas is
The maximum number of possible interference maxima for slitseparation equal to twice the wavelength in Young's doubleslit experiment, is
Two identical light waves, propagating in the same direction, have a phase difference δ . After they superpose the intensity of the resulting wave will be proportional to
When exposed to sunlight, thin films of oil on water often exhibit brilliant colours due to the phenomenon of
The transition from the state n = 4 to n = 3 in hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from
A capacitor of capacity C₁ is charged by connecting it across a battery of e.m.f. V₀. The battery is then removed and the capacitor is connected in parallel with an uncharged capacitor of capacity C₂. The potential difference across this combination is
If a particle of mass m is projected from the lowest point of smooth vertical circle of radius 'A' with velocity 5 a g the pressure at its lowest point will be—
A series combination of two resistors 1 Ω each is connected to a 12 V battery of internal resistance 0.4Ω. The current flowing through it is
The figure to the right shows an edgeon view of three extremely large, parallel insulating sheets positively charged with uniform and identical surface charge densities. In which of the regions shown is the electric field a maximum?
A straight wire of diameter 0.5 mm carrying a current of 1 A is replaced by another wire of 1 mm diameter carrying the same current. The strength of magnetic field far away is
Ethanol when reacted with PCl₅ gives A, POCl₃ and HCl. A reacts with silver nitrite to form B (major product) and AgCl. A and B respectively are :
Benzyl alcohol is obtained from benzaldehyde by
For a reaction, 2A + B → Products, the active mass of B is kept constant and that of A is doubled. The rate of reaction will then
A liquid is in equilibrium with its vapour at its boiling point. The molecules in these two phases will have equal
The densities of graphite and diamond at 298 K are 2.25 and 3.31 gcm^{3} respectively. If the standard free energy difference (ΔGº)is equal to 1895 Jmol^{1}, then pressure at which graphite will be transformed into diamond at 298 K is
Which of the following elements has the lowest ionisation potential
The ionisation potential increases from O to F to Ne, because of increasing nuclear charge. The ionisation potential is highest for Ne because of its stable (ns^{2} np^{6}) electronic configuration. But the ionisation potential of O is lower than N although the nuclear charge of O is higher. This is due to the extrastability of exactly halffilled 2porbitals of N.
The most stable complex among the following is
In the diazotisation of aniline the excess of hydrochloric acid is used primarily with sodium nitrite because it
The pair of compounds, in which both the metals are in their highest possible oxidation state, is
The aqueous solution of which of the following salt has the lowest pH value?
Why only As⁺³ gets precipitated as As₂S₃ and not Zn⁺² as ZnS when H₂S is passed through an acidic solution containing As⁺³ and Zn⁺²?
Which one of the following compounds will be most readily attacked by an electrophile?
Following carbocation changes to more stable carbocation :
Ethane is obtained from ethylene by which of the following methods?
A facecentred cubic element has a edge length of 400 pm. What is its density? At. weight of element= 60)
Which of the following does not represent a type of crystal system
2NHCl will have the same molar concentration is
An azeotropic mixture of two liquids boils at a lower temperature than either of these when
What is formed when calcium carbide reacts with heavy water?
For n = 5, total number of electrons will be ___Options
If Zaxis is te molecular axis, which of the following combination is not allowed for the formation of MO?Options
Which of the following statements is true ?Options
For a second order reaction, the time required for half change is _Options
Which one of the following highspin complexes has the largest CFSE (Crystal field stabilization energy)?Options
Cation with higher oxidation state has a larger value of CFSE and CFSE decrease with the increase of the number of delectrons.
In a Lassaigne's test for sulphur in the organic compound with sodium nitroprusside solution the purple colour formed is due toOptions
If (a2)+16(b2)+49(c2)4ab28bc7ac=0, then a,b,c are in:
The digit in the unit place of the number 2009!+3^{7886}2009!+37886 is
The volume of the solid obtained by rotating the ellipse (x²/a²) + (y²/b²) = 1 about axis of x isOptions
The centre and radius of the circle with the segment of the line x+y=1 cut of by the coordinate axes as diameter areOptions
If ω is nonreal cube root of unity then [(1 + 2ω + 3ω²) /(2 + 3ω + ω²)] + [(2 + 3ω + 3ω²)/(3 + 3ω + 2ω²)] is equal toOptions
The argument of the complex number 13−5i4−9i13−5i4−9i isOptions
If y (t) is solution of [(t +(dy∕dt)]  ty = 1, y (0) = 1. At t = 1 the solution is
If f(x)=cosx, 0≤x≤(π/2), the value of 'c' for which f(x) satisfies Mean Value theorem isOptions
If g(x) = x² + x  2 and 1/2 (gof) (x) = 2x²  5x + 2, then f(x) is equal toOptions
Which of the following is not a statement in logic ?
1. Earth is planet .
2. Plants are living object .
3. √−3−3 is rational number .
4. x^{2}  5x + 6 < 0, where x ∈−R∈−R
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A): The value of
Reason(R) :
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A): For x = r cos θ, y = r sin θ
The number 4.4 × 10^{6} ohms expressed using a metric prefix is
Equation of the tangent at (4,4) on x²=4y isOptions
The number of diagonals that can be drawn by joining the vertices of a heptagon is :Options
If x and y are related as y  4x = 3, then the nature of correlation between x and y isOptions
The foot of perpendicular from (2,4) on the line x+y=1 isOptions
The equation of the normal to the curve y=sinx at (π,0) isOptions
Which of the following lines passes through the centre of the sphere x² + y² + z² + 4x  4z = 0Options
The one root of the equation cosxx+(1/2)=0 lies in the intervalOptions
If the position vectors of A and B are i+3jk and 3ij3k respectively, then the position vector of mid point of AB isOptions
If a = i + 2 j + 3k, b =  i + 2 j + k and c = 3 i + j and a + tb is perpendicular to c, the value of t is
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer
Assertion(A):The inverse of does not exist.
Reason(R): The matrix is nonsingular.
The minimum distance from the point (4, 2) to the parabola y2 = 8x isOptions
Let f(x) =ax²+bx+c,a≠0 and triangle = b²4ac.If α+β, α²+β² and α³+β³ are in G.P., then :Options
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