Recent questions tagged 10

Which of the following reactions are disproportionation reaction ? (a)$2Cu^{+} \to Cu^{2+}+Cu^0$ (b)$3MnO_4^{2-}+4H^{+} \to 2MnO_4^{-}+MnO_2$ (c)$2KMnO_4 \underrightarrow{\qquad \Delta \qquad } K_2MnO_4 +MnO_2 +O_2$ (d)$2MnO_4^{-}+3Mn^{2+}+2H_2O \longrightarrow 5MnO_2+4H^{\oplus}$ Select the correct option from the following

asked Jul 8, 2019 by pady_1

1 answer

Dimensions of ohm are same as (h = Planck's constant, e = charge) :

asked Dec 19, 2018 by pady_1

0 answers

The S.I unit of moment of inertia is :

asked Dec 19, 2018 by pady_1

0 answers

In a compound microscope cross wires are fixed at the point :

asked Dec 19, 2018 by pady_1

1 answer

Light waves producing interference have their amplitudes in the ratio $3:2$. The intensity ratio of maximum and minimum of interference fringes is :

asked Dec 11, 2018 by pady_1

0 answers

If 13.6 eV energy is required to ionize the hydrogen atom, then the energy required to remove an electrons from $n=2$ is :

asked Dec 11, 2018 by pady_1

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Consider telecommunication through optical fibres. Which of the following statements is not true ?

asked Dec 11, 2018 by pady_1

0 answers

The reading of the ammeter for a silicon diode in the given circuit is :

asked Dec 11, 2018 by pady_1

0 answers

If for $x \in (0, \frac{1}{4})$, the derivative of $\tan^{-1} \begin{pmatrix} \frac{6x \sqrt{x}}{1-9x^3} \end{pmatrix}$ is $\sqrt{x}. g(x)$, then $g(x)$ equals :

asked Dec 11, 2018 by pady_1

1 answer

A particle performs simple harmonic motion with amplitude A. Its speed is trebled at the instant that it is at a distance $\frac{2A}{3} $ from equilibrium position. The new amplitude of the motion is :

asked Dec 11, 2018 by pady_1

0 answers

An ideal gas goes through a reversible cycle $a \to b \to c \to d$ has the $V-T$ diagram shown below. Process $d \to a$ and $b \to c$ are adiabatic. The corresponding $P - V$ diagram for the process is (all figures are schematic and not drawn to scale) :

asked Dec 11, 2018 by pady_1

0 answers

In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1kW. The voltage of the electric mains is 220 V. The minimum capacity of the main fuse of the building will be :

asked Dec 11, 2018 by pady_1

0 answers

Which one of the following molecules is expected to exhibit diamagnetic behaviour ?

asked Dec 11, 2018 by pady_1

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If 100 times the $100^{th}$ term of an AP with non zero common difference equal the 50 times its $50^{th} $ term, then the $150^{th}$ term of this AP is

asked Dec 11, 2018 by pady_1

1 answer

An object moving with a speed of 6.25 m/s, is decelerated at a rate given by : $\frac{dv}{dt} = -2.5 \sqrt{v}$ where $v$ is the instantaneous speed. The time taken by the object, to come to rest, would be :

asked Dec 11, 2018 by pady_1

0 answers

$29.5\; mg$ of an organic compound containing nitrogen was digested according to Kjeldahl’s method and the evolved ammonia was absorbed in $20\; mL$ of $0.1\; M\; HCl$ solution. The excess of the acid required $15\; mL$ of $0.1\; M \;NaOH$ solution for complete neutralization. The percentage of nitrogen in the compound is

asked Dec 11, 2018 by pady_1

0 answers

One kg of a diatomic gas is at a pressure of $8 \times 10^4\;N/m^2$. The density of the gas is $4\; kg/m^{3}$. What is the energy of the gas due to its thermal motion ?

asked Nov 29, 2018 by pady_1

0 answers

The perpendicular bisector of the line segment joining P (1, 4) and Q (k, 3) has y-intercept - 4. Then a possible value of k is

asked Nov 29, 2018 by pady_1

0 answers

The differential equation of all circles passing through the origin and having their centres on the $x-axis$ is :

asked Nov 29, 2018 by pady_1

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A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work done by the force of gravity during the time the particle goes up is :

asked Nov 13, 2018 by pady_1

0 answers

ABC is a triangle. Forces $\overrightarrow{P}, \overrightarrow{Q}, \overrightarrow{R}$ acting along $IA, IB$ and $IC$ respectively are in equilibrium, where $I$ is the incentre of $\Delta ABC$. Then $\overrightarrow{P} : \overrightarrow{Q} : \overrightarrow{R}$ is :

asked Nov 5, 2018 by pady_1

0 answers

A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at $2\;m/s^2$. he reaches the ground with a speed of $3 \; m/s$. At what height, did he bail out ?

asked Nov 5, 2018 by pady_1

0 answers

If $(1-p)$ is a root of quadratic equation $x^2 + px + (1-p) =0$, then its roots are

asked Nov 5, 2018 by pady_1

0 answers

A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from

asked Aug 21, 2018 by pady_1

1 answer

With respect to the conformers of ethane, which of the following statements is true?

asked Aug 21, 2018 by pady_1

1 answer

The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is:

asked Aug 21, 2018 by pady_1

1 answer

Strong reducing behaviour of $H_3PO_2$ is due to :

asked Aug 21, 2018 by pady_1

1 answer

The ratio of the acceleration for a solid sphere (mass 'm' and radius 'R') rolling down an incline of angle 'θ' without slipping and slipping down the incline without rolling is :

asked Aug 20, 2018 by pady_1

1 answer

A body of mass 'm' is taken from the earth's surface to the height equal to twice the radius (R) of the earth. The change in potential energy of body will be -

asked Aug 20, 2018 by pady_1

2 answers

ABC is an equilateral triangle with O as its centre $\overrightarrow{F_1},\overrightarrow{F_2} and \overrightarrow{F_3}$ represent three forces acting along the sides AB, BC and AC respectively. If the torque about O is zero then the magnitude of $\overrightarrow{F_3}$ is

asked Aug 20, 2018 by pady_1

1 answer

A radioactive nucleus of mass M emits a photon of frequency $\nu$ and the nucleus recoils. The recoil energy will be -

asked Aug 16, 2018 by pady_1

1 answer

The period of oscillation of a mass M suspended from a spring of negligible mass is T. If along with it another mass M is also suspended, the period of oscillation will now be

asked Jul 26, 2018 by pady_1

1 answer

A body, under the action of a force $\overrightarrow{F}=6\widehat{i}-8\widehat{j}+10\widehat{k}$, acquires an acceleration of $1m/s^{2}$. The mass of this body must be :

asked Jul 26, 2018 by pady_1

1 answer

A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 $ms^{–1}$ to 20 $ms^{–1}$ while passing through a distance 135 m in t second. The value of t is -

asked Jul 26, 2018 by pady_1

1 answer

A mass of $2.0 kg$ is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring and the pan is negligible. When pressed slightly and released the mass executes a simple harmonic motion. The spring constant is $200N/m$. What should be the minimum amplitude of the motion so that the mass gets detached from the pan (Take $g = 10 m/s^2$) <img src =""/>

asked Jul 26, 2018 by pady_1

1 answer

The binding energy of deuteron is 2.2 MeV and that of $_{2}^{4}HE$ is 28MeV. If two deuterons are fused to form one$_{2}^{4}HE$ then the energy released is:-

asked Jul 25, 2018 by pady_1

1 answer

As per this diagram a point charge +q is placed at the origin O. Work done in taking another point charge â€“Q from the point A coordinates (0, a) to another point B coordinates (a, 0) along the straight path AB is

asked Jul 24, 2018 by pady_1

1 answer

The density of newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R, the radius of the planet would be :-

asked Jul 24, 2018 by pady_1

1 answer

A ball rolls without slipping. The radius of gyration of the ball about an axis passing through its centre of mass is K. If radius of the ball be R, then the fraction of total energy associated with its rotational energy will be :

asked Jul 24, 2018 by pady_1

1 answer

When ultraviolet rays incident on metal plate then photoelectric effect does not occur, it occurs by incidence of : -

asked Jul 23, 2018 by pady_1

1 answer

The current (I) in the circuit will be : -

asked Jul 20, 2018 by pady_1

1 answer

A body of weight 72 N moves from the surface of earth at a height half of the radius of the earth, then gravitational force exerted on it will be :

asked Jul 20, 2018 by pady_1

2 answers