Recent questions tagged 2019

When an object is shot from the bottom of a long smooth inclined plane kept at an angle 60° with horizontal, it can travel a distance $x_1$ along the plane. But when the inclination is decreased to 30° and the same object the shot with the same velocity, it can travel $x-2$ distance. Then $x_1 : x_2$ will be

asked Jul 8, 2019 by pady_1

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An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is, (nearly):$(m_c=9\times10^{-31}kg)$

asked Jul 8, 2019 by pady_1

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$\alpha-particle$ consists of :

asked Jul 8, 2019 by pady_1

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In the circuits shown below, the readings of the voltmeters and the ammeters will be:

asked Jul 8, 2019 by pady_1

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A parallel plate capacitor of capacitance $20\mu F$ is being charged by a voltage source whose potential is changing at the rate of $3\frac{ V}{s}$. The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively :

asked Jul 8, 2019 by pady_1

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Which of the following acts as a circuit protection device?

asked Jul 8, 2019 by pady_1

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For a p-type semiconductor which of the following statements is true?

asked Jul 8, 2019 by pady_1

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Two parallel infinite line charges with linear charge densities$\lambda +\frac{C}{m} \;and \;-\lambda \frac{C}{m}$ are placed at a distance of 2R in free space. What is the electric field midway between two line charges?

asked Jul 8, 2019 by pady_1

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In total internal reflection when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be angle

asked Jul 8, 2019 by pady_1

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Two similar thin equi-convex lenses, of focal length f each, are kept coaxially in contact with each other such that the focal length of the combination is $F_1$.When the space between the two lenses is filled with glycerin (which has the same refractive index $(\mu = 1.5)$ as that of glass) then the equivalent focal length is $F_2$. The ratio $F_1 : F_2$ will be :

asked Jul 8, 2019 by pady_1

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Two particles A and B are moving in uniform circular motion in concentric circles of radius rA and rB with speed uA and uB respectively. The time period of roation is the same. The ratio of angular speed of A to that of B will be :

asked Jul 8, 2019 by pady_1

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Pick the wrong answer in the context with rainbow.

asked Jul 8, 2019 by pady_1

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A force $F = 20 + 10y$ acts on a particle in y-direction where F is in newton and y in meter. Work done by this force to move the particle from $y = 0$ to $y = 1;m$ is :

asked Jul 8, 2019 by pady_1

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At a point A on the earth's surface the angle of dip, $\delta = +25^{\circ}$. At a point B on the earth's surface the angle of dip, $\delta =-25^{\circ}$. We can interpret that.

asked Jul 8, 2019 by pady_1

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Six similar bulbs are connected as shown in the figure with a DC source of emf E, and zero internal resistance. The ratio of power consumption by the bulbs when (i) all are glowing and (ii) in the situation when two from section A and one from section B are glowing, will be :

asked Jul 8, 2019 by pady_1

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In which of the following devices, the eddy current effect is not used ?

asked Jul 8, 2019 by pady_1

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A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at a distance r from the centre :

asked Jul 8, 2019 by pady_1

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The radius of circle the period of revolution initial position and sense of revolution are indicated in the fig

y-projection of the radius vector of rotating particle P is:

asked Jul 8, 2019 by pady_1

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A solid cylinder of mass 2 kg and radius 4 cm is rotating about its axis at the rate of 3 rpm. The torque required to stop after $2\pi$ revolutions is :

asked Jul 8, 2019 by pady_1

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Which colour of the light has the longest wavelength ?

asked Jul 8, 2019 by pady_1

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A body weighs 200 N on the surface of the earth.How much will it weigh half way down to the centre of the earth ?

asked Jul 8, 2019 by pady_1

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In an experiment, the percentage of error occurred in the measurment of physical quantities A, B, C and D are 1%, 2%, 3% and 4% respectively. Then the maximum percentage of error in the measurement X, where $X=\frac{A^2B^\frac{1}{2}}{C^\frac{1}{3}D^3}$, will be

asked Jul 8, 2019 by pady_1

1 answer

A disc of radius 2m and mass 100 kg rolls on a horizontal floor.Its center of mass has speed of $20\frac{cm}{s}$.How much work is needed to stop it?

asked Jul 8, 2019 by pady_1

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When a block of mass M is suspended by a long wire of length L, the length of the wire become (L+l).The elastic potential energy stored in the extended wire is

asked Jul 8, 2019 by pady_1

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The unit of thermal conductivity is

asked Jul 8, 2019 by pady_1

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A copper rod of 88 cm and an aluminum rod of unknown length have their increase in length independent of increase in temperature. The length of aluminum rod is : ($\propto Cu=1.7\times10^{-5}K^{-1}and \propto Al=2.2\times 10^{-5}K^{-1}$)

asked Jul 8, 2019 by pady_1

1 answer

A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of $2.5 \times 10^{-2}$ $\frac{ N}{m}$. The pressure inside the bubble equals at a point $Z_0$ below the free surface of water in a container. Taking $g = 10 \frac{m}{s^2} $ density of water $= 103\frac{ kg}{m^3}$, the value of $Z_0$ is :-

asked Jul 8, 2019 by pady_1

1 answer

Average velocity of a particle executing SHM in one complete vibration is :

asked Jul 8, 2019 by pady_1

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A 800 turn coil of effective area $0.05 m^2$ is kept perpendicular to a magnetic field $5\times 10^{5}$ T. When the plane of the coil is rotated by 90° around any of its coplanar axis in 0.1 s, the emf induced in the coil will be :

asked Jul 8, 2019 by pady_1

1 answer

The displacement of a particle executing simple harmonic motion is given by $y = A0 + Asin{\omega}{t}+ Bcos\omega{t}$. Then the amplitude of its oscillation is given by :

asked Jul 8, 2019 by pady_1

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A mass m is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when:

asked Jul 8, 2019 by pady_1

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The speed of a swimmer in still water is $20\frac{ m}{s}$. The speed of river water is $10 \frac{m}{s}$ and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path, the angle at which he should make his strokes w.r.t. north is given by :

asked Jul 8, 2019 by pady_1

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Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is :

asked Jul 8, 2019 by pady_1

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A block of mass 10 kg is in contact against the inner wall of a hollow cylindrical drum of radius 1 m. The coefficient of friction between the block and the inner wall of the cylinder is 0.1. The minimum angular velocity needed for the cylinder to keep the block stationary when the cylinder is vertical and rotating about its axis, will be :$(g = 10\frac{m}{s^2})$

asked Jul 8, 2019 by pady_1

1 answer

The correct Boolean operation represented by the circuit diagram drawn is

asked Jul 8, 2019 by pady_1

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The total energy of an electron in an atom in an orbit is -3.4 eV. Its kinetic and potential energies are, respectively :

asked Jul 8, 2019 by pady_1

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Increase in temperature of a gas filled in a container would lead to :

asked Jul 8, 2019 by pady_1

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In which of the following processes, heat is neither absorbed nor released by a system ?

asked Jul 8, 2019 by pady_1

1 answer

The method used to remove temporary hardness of water is :

asked Jul 8, 2019 by pady_1

2 answers

What is the correct electronic configuration of the central atom in $K_4[Fe(CN)_6]$ based on crystal field theory?

asked Jul 8, 2019 by pady_1

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For the chemical reaction $N_2(g)+3H_2(g)\rightleftharpoons 2NH_3(g)$ the correct option is :

asked Jul 8, 2019 by pady_1

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The major product of the following reaction is :

asked Jul 8, 2019 by pady_1

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Among the following, the reaction that proceeds through an electrophilic substitution is :

asked Jul 8, 2019 by pady_1

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A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is :

asked Jul 8, 2019 by pady_1

1 answer

The non-essential amino acid among the following is :

asked Jul 8, 2019 by pady_1

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Which of the following is incorrect statement ?

asked Jul 8, 2019 by pady_1

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Match the following (a)Pure nitrogen (i) Chlorine (b) Haber process (ii) Sulphuric acid (c) Contact process (iii) Ammonia (d) Deacon's process (iv) Sodium azide or Barium azid Which of the following is the correct option ? (a) (b) (c) (d) (1) (i) (ii) (iii) (iv) (2) (ii) (iv) (i) (iii) (3) (iii) (iv) (ii) (i) (4) (iv) (iii) (ii) (i)

asked Jul 8, 2019 by pady_1

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In which case change in entropy is negative ?

asked Jul 8, 2019 by pady_1

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For the cell reaction $2Fe^{3+}(aq)+2I^{-}(aq)\rightarrow2Fe^{2+}(aq)+I_2(aq)$ $E^{\ominus}_{cell}$ cell E 0.24V at 298 K. The standard Gibbs energy $(\triangle^{\circ}_{r}G^{\ominus})$of the cell reaction is : [Given that Faraday constant $F = 96500 C \;mol^{-1}$

asked Jul 8, 2019 by pady_1

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The mixture that forms maximum boiling azeotrope is :

asked Jul 8, 2019 by pady_1

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