Recent questions tagged 83

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

1 answer

Which one of the following reactions is an example of calcination process ?

asked Dec 19, 2018 by pady_1

0 answers

The activity of a radioactive element is $2 \times 10^{10}$ disintegration per second. After ten minutes the activity is reduced to $2 \times 10^9$ distintegrations per second. The disintegration constant of the radioactive element is :

asked Dec 19, 2018 by pady_1

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The half-life of a radioactive element is 100 years. What is its disintegration contant (in years$^{-1}$) ?

asked Dec 19, 2018 by pady_1

1 answer

In a nuclide, one a.m.u of mass is dissipated into energy to bind its nucleons. The energy equivalent of this mass is :

asked Dec 11, 2018 by pady_1

1 answer

For the following cell with hydrogen electrodes at two different pressure $p_1$ and $p_2$<br>

asked Dec 11, 2018 by pady_1

0 answers

Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite :

asked Dec 11, 2018 by pady_1

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The predominant form of histamine present in human blood is ($pK_a$ , Histidine = 6.0)

asked Dec 11, 2018 by pady_1

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The group having isoelectronic species is :

asked Dec 11, 2018 by pady_1

1 answer

The distance of the point $(1, −5, 9)$ from the plane $x−y+z=5$ measured along the line $x=y=z$ is :

asked Dec 11, 2018 by pady_1

1 answer

If the points $(1, 1, \lambda)$ and $(-3, 0, 1)$ are equidistant from the plane, $3x+4y+12z+13=0$, then $\lambda$ satisfies the equation :

asked Dec 11, 2018 by pady_1

1 answer

The correct set of four quantum numbers for the valence elections of rubidium atom (Z= 37) is:

asked Dec 11, 2018 by pady_1

0 answers

A circular loop of radius 0.3 cm lies parallel to a much bigger circular loop of radius 20 cm. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is 15 cm. If a current of 2.0 A flows through the smaller loop, then the flux linked with bigger loop is

asked Dec 11, 2018 by pady_1

0 answers

Which branched chain isomer of the hydrocarbon with molecular mass 72 u gives only one isomer of mono substituted alky halide ?

asked Dec 11, 2018 by pady_1

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Ozonolysis of an organic compound gives formaldehyde as one of the products.. This confirms the presence of :

asked Dec 11, 2018 by pady_1

1 answer

Let $f : R \to R$ be a positive increasing function with $\displaystyle\lim_{x \to \infty} \frac{f(3x)}{f(x)} = 1$ Then $\displaystyle\lim_{x \to \infty} \frac{f(2x)}{f(x)} = $

asked Dec 11, 2018 by pady_1

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The area of the region bounded by the parabola $(y-2)^2 = x-1$, the tangent to the parabola at the point (2, 3) and the x-axis is

asked Nov 29, 2018 by pady_1

0 answers

78. A parallel plate capacitor with air between the plates has a capacitance of 9 pF. The separation between its plates is ‘d’. The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant $K_1=3$ and thickness $\frac{d}{3}$ while the other one has dielectric constant $K_2 = 6$ and thickness $\frac{2d}{3}$. Capacitance of the capacitor is now

asked Nov 29, 2018 by pady_1

0 answers

The $pK_a$ of a weak acid (HA) is 4.5. The pOH of an aqueous buffered solution of HA in which 50% of the acid ionised is :

asked Nov 29, 2018 by pady_1

0 answers

In which of the following molecules / ions all the bonds are not equal ?

asked Nov 13, 2018 by pady_1

0 answers

For a spontaneous reaction the $\Delta G$, equilibrium constant $(K)$ and $E_{cell}^{\circ}$ will be respectively :

asked Nov 5, 2018 by pady_1

0 answers

The bond order in NO is 2.5 while that in $NO^+$ is 3. Which of the following statements is true for these two species ?

asked Nov 5, 2018 by pady_1

1 answer

Which one of the following ions exhibits d-d transition and paramagnetism as well ?

asked Aug 21, 2018 by pady_1

1 answer

Select the mismatch :<br>

asked Aug 21, 2018 by pady_1

1 answer

Which of the following pairs of hormones are not antagonitic (having opposite effects) to each other ? <br>

asked Aug 21, 2018 by pady_1

1 answer

Acid rain is caused by increase in the atmospheric concentration of -

asked Aug 21, 2018 by pady_1

2 answers

In the Kjedahl's method for estimation of nitrogen present in soil sample, ammonia evolved from 0.75g of sample neutralized 10 ml. of 1M $H_2SO_4$ The percentage of nitrogen in the soil is:

asked Aug 20, 2018 by pady_1

1 answer

Some meta - directing substitution in aromatic substitution are given. Which one is most deactivating ?

asked Aug 20, 2018 by pady_1

1 answer

The pair of species with the same bond order is

asked Aug 20, 2018 by pady_1

1 answer

The d-electron configurations of $Cr^{2+}, Mn^{2+}, Fe^{2+}$ and $Co^{2+}$ are $d^4, d^5, d^6$ and $d^7$ respectively. Which one of the following will exhibit minimum paramagnetic behaviour ? <br> (At. Nos. Cr= 24, Mn= 25, Fe= 26, Co = 27)

asked Aug 16, 2018 by pady_1

1 answer

Property of the alkaline earth metals that increases with their atomic number:

asked Jul 26, 2018 by pady_1

1 answer

Amongst the element with following electronic configurations, which one of them may have the highest ionization energy ?

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following is an amine hormone ?

asked Jul 26, 2018 by pady_1

1 answer

Which of the following will give a pair of enantiomorphs:($en = NH_2 CH_2 CH_2 NH_2$)

asked Jul 26, 2018 by pady_1

1 answer

The hydrogen ion concentration of a $10^{–8}$M HCl aqueous solution at $298 K (K_W = 10^{–14}) $is:-

asked Jul 25, 2018 by pady_1

0 answers

Electrolytic reduction of nitrobenzene in weakly acidic medium gives :-

asked Jul 24, 2018 by pady_1

1 answer

A compound formed by elements X and Y crystallizes in a cubic structure in which the X atoms are at the corners of a cube and the Y atoms are at the face-centers. The formula of the compound is :-

asked Jul 24, 2018 by pady_1

1 answer

The correct order of ionic radii of $Y^{3+}, La^{3+}, Eu^{3+}$, and $Lu^{3+}$ is : -

asked Jul 24, 2018 by pady_1

1 answer

In borax bead test which compound is formed

asked Jul 23, 2018 by pady_1

1 answer

Which of the following statement is not correct

asked Jul 20, 2018 by pady_1

1 answer

Mg is present in :

asked Jul 20, 2018 by pady_1

1 answer

Maximum impurity in Pig iron will be of :

asked Jun 15, 2018 by pady_1

1 answer

what is the central value for 3 and 7?

asked Dec 31, 2015 by pady_1

0 answers

What will be the labor charge for tiling a hall 22 m long and 17 m wide at the rate of $ 8 per sq. m?

asked Dec 31, 2015 by pady_1

1 answer

16 students and 7 teachers went on a field trip to an art museum. Student tickets cost Rs 495 each, and adult tickets cost Rs 728 each. How much did the museum tickets cost in all?

asked Dec 31, 2015 by pady_1

1 answer

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