Recent questions tagged 40

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

A galvanometer has a resistance of $50 \; \Omega$ and a current of $0.01 \;A$ will cause full scale deflection. To convert this into an ammeter with full scale deflection for $5 \;A$, we have to connect approximately :

asked Dec 19, 2018 by pady_1

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The electric field intensity in air at a point $20\; cm$ from a point charge $Q$ coulombs is $4.5 \times 10^5\;N/C$. The magnitude of $Q$ is :

asked Dec 19, 2018 by pady_1

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When a liquid in a glass vessel, is heated its apparent expansion is $10.30 \times 10^{-4}/^{\circ}C$ same liquid when heated in a metal its apparent expansion $10.06 \times 10^{-4}/^{\circ}C$. The coefficient of linear expansion of the metal is : (coefficient of linear expansion of glass = $9 \times 10^{-6}/^{\circ}C$) :

asked Dec 19, 2018 by pady_1

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A particle is projected up along a rough inclined plane of inclination $45^{\circ}$ with the horizontal. If the coefficient of friction is $0.5$, the acceleration is : (g = Acceleration due to gravity)

asked Dec 11, 2018 by pady_1

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The kinetic energy needed to project a body of mass $m$ from the earth's surface (radius R) to infinity is :

asked Dec 11, 2018 by pady_1

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When the current changes from +2A to -2A in 0.05 s, an emf of 8 V is induced in a coil. The coefficient of self-induction of the coil is :

asked Dec 11, 2018 by pady_1

0 answers

Let $f(x) = x^2 + \frac{1}{x^2} $ and $g(x) = x - \frac{1}{x},\; x \in R -\{-1, 0, 1\}$. If $h(x) = \frac{f(x)}{g(x)}$, then the local minimum value of $h(x)$ is :

asked Dec 11, 2018 by pady_1

1 answer

In a Young's double slit experiment, slits are separated by 0.5 mm, and the screen is placed 150 cm away. A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is :

asked Dec 11, 2018 by pady_1

0 answers

For a linear plot of $\log (x/m)$ versus $\log p$ in a Freundlich adsorption isotherm, which of the following statements is correct ? ($k$ and $n$ are constants)

asked Dec 11, 2018 by pady_1

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

asked Dec 11, 2018 by pady_1

0 answers

The integral $\begin{align} \int \begin{pmatrix}1 + x - \frac{1}{x} \end{pmatrix} e^{x + \frac{1}{x}} dx \end{align}$ is equal to

asked Dec 11, 2018 by pady_1

1 answer

The intercepts on x-axis made by tangents to the curve, $\begin{align} y = \int_0^x |t| dt. x \in R \end{align}$. which are parallel to the line $y = 2x$, are equal to

asked Dec 11, 2018 by pady_1

1 answer

In Young's double slit experiment, one of the slit is wider than other, so that the amplitude of the light from one slit is double of that from other slit. If $I_m$ be the maximum intensity, the resultant intensity $I$ when they interfere at phase difference $\phi$ is given by

asked Dec 11, 2018 by pady_1

0 answers

Let $\alpha, \beta$ be real and $z$ be a complex number. If $z^2 + \alpha z + \beta = 0$ has two distinct roots on the line $Rez=1$, then it is necessary that

asked Dec 11, 2018 by pady_1

0 answers

The binding energy per nucleon for the parent nucleus is $E_1$ and that for the daughter nuclei is $E_2$.Then

asked Dec 11, 2018 by pady_1

0 answers

In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer. The reaction is $CH_3OH (\ell) + \frac{3}{2} O_2 (g) \to CO_2 (g) + 2H_2O (\ell)$ at 298 K standard Gibb's energies of formation for $CH_3OH (\ell), H_2O (\ell) $ and $CO_2 (g)$ are $-166.2, -237.2 $ and $-394.4$ $kJ\; mol^{-1}$ respectively. If standard enthalpy of combustion of methanol is $-726\; kJ\; mol^{-1}$, efficiency of the fuel cell will be

asked Nov 29, 2018 by pady_1

0 answers

Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives

asked Nov 29, 2018 by pady_1

0 answers

If the difference between the roots of the equation $x^2 + ax + 1 = 0$ is less than $\sqrt{5}$, then the set of possible values of $a$ is :

asked Nov 29, 2018 by pady_1

0 answers

If the binding energy per nucleon in $_3^7 Li$ and $_2^4 He$ nuclei are 5.60 MeV and 7.06 MeV respectively, then in the reaction : <br> $p + _3^7 Li \to 2 _2^4 He$ <br> energy of proton must be :

asked Nov 13, 2018 by pady_1

0 answers

Let $f(x)$ be a non-negative continuous function such that the area bounded by the curve $y=f(x)$, $x-axis$ and the ordinates $x=\frac{\pi}{4}$ and $x=\beta > \pi/4$ is <br> $( \beta \sin \beta + \frac{\pi}{4} \cos \beta + \sqrt{2} \beta)$. Then $f(\frac{\pi}{2})$ is :

asked Nov 5, 2018 by pady_1

0 answers

Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye ? [Take wavelength of light = 500 nm]

asked Nov 5, 2018 by pady_1

0 answers

If $\begin{align} \int_0^{\pi} x f (\sin x) dx = A \int_0^{\pi/2} f(\sin x) dx \end{align}$, then A is

asked Nov 5, 2018 by pady_1

0 answers

The power radiated by a black body is P and it radiates maximum energy at wavelength, $\lambda_0$. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength $\frac{3}{4} \lambda_D$, the power radiated by it becomes nP. The value of n is

asked Aug 21, 2018 by pady_1

1 answer

Ionic mobility of which of the following alkali metal ions is lowest when aqueous solutions of their salts are put under an electric filed?

asked Aug 21, 2018 by pady_1

1 answer

Which of the following statement about hydrogen is incorrect ?

asked Aug 21, 2018 by pady_1

1 answer

The oxidation of benzene by $V_2O_5$ in the presence of air produces -

asked Aug 21, 2018 by pady_1

1 answer

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de-Broglie wavelength of the particle is:

asked Aug 20, 2018 by pady_1

1 answer

For a normal eye, the cornea of eye provides a converging power of 40D and the least converging power of the eye lens behind the cornea is 20D. Using this information, the distance between the retina and the corneaeye lens can be estimated to be -

asked Aug 20, 2018 by pady_1

1 answer

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is

asked Aug 20, 2018 by pady_1

1 answer

Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de-Broglie wavelength associated with the electrons would

asked Aug 16, 2018 by pady_1

2 answers

A source $S_1$ is producing, $10^{15}$ photons per second of wavelength 5000 Å. Another source $S_2$ is producing 1.02 × $10^{15}$ photons per second of wavelength 5100 Å. Then, (power of $S_2$)/(power of $S_1$) is equal to –

asked Jul 26, 2018 by pady_1

1 answer

Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a target irradiated by this beam is :

asked Jul 26, 2018 by pady_1

1 answer

Three forces acting on a body are shown in the figure. To have the resultant force only along the y-direction, the magnitude of the minimum additional force needed is - <br>

asked Jul 26, 2018 by pady_1

1 answer

Monochromatic light of frequency $6.0 \times 10^{14}$ Hz is produced by a laser. The power emitted is $2 \times 10^{-3}$W. The number of photons emitted, on the average, by the source per second is :-

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following statements is true:

asked Jul 25, 2018 by pady_1

1 answer

If a vector $2\hat{i} + 3\hat{j}+8\hat{k}$ is perpendicular to the vector 4j- 4i + ak , then the value of ?

asked Jul 24, 2018 by pady_1

1 answer

The coefficient of static friction, µs, between block A of mass 2 kg and the table as shown in the figure is 0.2. What would be the maximum mass value of block B so that the two blocks do not move ? The string and the pulley are assumed to be smooth and massless. ($g = 10 m/s^{2}$)

asked Jul 24, 2018 by pady_1

2 answers

J.J. Thomson's cathode-ray tube experiment demonstrated that

asked Jul 24, 2018 by pady_1

1 answer

For a cell terminal P.D. is 2.2V when circuit is open and reduces to 1.8V when cell is connected to a resistance of R = 5$\Omega$. Determine internal resistance of cell (r) is then : -

asked Jul 23, 2018 by pady_1

1 answer

The interplaner distance in a crystal is $2.8\times 10^{-8}$ m. The value of maximum wavelength which can be diffracted

asked Jul 20, 2018 by pady_1

1 answer

Two bulbs of (40 W, 200 V), and (100 W, 200 V). Then correct relation for their resistance :

asked Jul 20, 2018 by pady_1

1 answer

Electric field at the equator of a dipole is E. If strength and distance is now doubled then the electric field will be :

asked Jun 15, 2018 by pady_1

1 answer

There are red and green balls in a bag. Two-third of the balls are red. If 5 red and 12 green more balls are added to the bag, which of following is correct?

asked Dec 31, 2015 by pady_1

1 answer

The number of lines of a symmetry in a ruler is

asked Dec 31, 2015 by pady_1

1 answer

Add 19.043 l, 14.109 l, and 2.001 l.

asked Dec 31, 2015 by pady_1

0 answers

$11 \large\frac{9}{9} \div \large\frac{12}{7}$

asked Dec 31, 2015 by pady_1

0 answers

A man earns \$ 450 per month. He spends $70\%$ of his income. What does he save every month?

asked Dec 31, 2015 by pady_1

0 answers

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