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6 months ago

Class 12th Chemistry

If O₂ gas is bubbled through water at 303 K, the number of millimoles of O₂ gas that dissolve in 1 litre of water is______________. (Nearest integer)

(Given: Henry’s Law constant for O₂ at 303 K is 46.82 k bar and partial pressure of O₂ = 0.920 bar)

(Assume solubility of O₂ in water in too small, nearly negligible)

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Class 12th Chemistry

Ionic radii of cation A⁺ and anion B^- are 102 and 181 pm respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for B^-. A⁺ is present in all octahedral voids. The edge length of the unit cell of the crystal AB is________ pm.

(Nearest integer)

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Payal Gupta

Contributor-Level 10

$d = \frac{Z M}{N_{A} a^{3}} = \frac{4 * 58.5}{6.02 * 1 0^{23} * a^{3}}$

$43.1 = \frac{4 * 58.5}{6.02 * 1 0^{23} * a^{3}}$

$∴ a = 2.08 * 1 0^{- 8} c m$

$∴ r_{N a^{+}} + r_{C l^{-}} = 1.04 * 1 0^{- 10}$ m

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Class 12th Chemistry Electrochemistry

Resistance of a conductivity cell (cell constant 129 m^-¹) filled with 74.5 ppm solution of KCl is $100 Ω$ (labeled as solution 1). When the same cell is filled with KCl solution of 149 ppm, the resistance is $50 Ω$ (labeled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. $\frac{\land_{1}}{\land_{2}} = x * 1 0^{- 3} .$ The value of x is________. (Nearest integer)

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Payal Gupta

Contributor-Level 10

Molar mass of C₇H₅N₃O₆= 12 * 7 + 1 * 5 + 14 * 3 + 16 * 6 = 84 + 42 + 96 = 227 g/mol

Number of moles = $\frac{681}{227}$ = 3 mol

$∴$ number of N-atoms

$= 3 * 6.02 * 1 0^{23} * 3 = 9 * 6.02 * 1 0^{23}$

$= 5418 * 1 0^{21}$

$∴ x = 5418$

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6 months ago

Class 12th Physics

If the potential barrier across a p-n junction is 0.6 V. Then the electric field intensity, in the depletion region having the width of 6 * 10^-⁶m, will be________ * 10⁵ N/C.

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Vishal Baghel

Contributor-Level 10

As, Ed = VB

$∴ E = \frac{V_{B}}{d} = \frac{0.6}{6 * 1 0^{- 6}} = 1 * 1 0^{5} N / C$

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6 months ago

Class 12th Physics

The X-Y plane be taken as the boundary between two transparent media M₁ and M₂. M₁ in $z \geq 0$ has a refractive index of $\sqrt[]{2}$ and M₂ with Z < 0 has refractive index of $\sqrt[]{3} .$ A ray of light travelling in M₁ along the direction given by the vector $\vec{P} = 4 \sqrt[]{3} \hat{i} - 3 \sqrt[]{3} \hat{j} - 5 \hat{k},$ is incident on the plane of separation. The value of difference between the angle of incident in M₁ and the angle of refraction in M₂ will be_______ degree.

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Vishal Baghel

Contributor-Level 10

For angle of incidence 'i' :-

cos I = $\frac{5}{\sqrt[]{48 + 27 + 25}} = \frac{5}{\sqrt[]{100}}$

=> I = 60°

Using snell's law :-

$μ_{1} s i n i = μ_{2} s i n r$

sin r = $\frac{\sqrt[]{2}}{\sqrt[]{3}} s i n 60 ° = \sqrt[]{\frac{2}{3}} * \frac{\sqrt[]{3}}{2} = \frac{1}{\sqrt[]{2}}$

$∴ r = 45 °$

So, difference, I – r = 60° - 45² = 15°

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6 months ago

Class 12th Physics Moving Charges and Magnetism

A wire of length 314cm carrying current of 14A is bent to form a circle. The magnetic moment of the coil is_________ A -m². [Given π = 3.14]

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Vishal Baghel

Contributor-Level 10

^{$l = 2 π r$}

^{$\Rightarrow 314 c m = 2 * 3.14 r$}

^{$\Rightarrow r = \frac{1}{2} m = 0.5 m$}

^{$μ = i A$}

^{$= 14 * π r^{2}$}

^{$= 1 4^{2} * \frac{22}{7} * \frac{1}{4} = 11$}

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6 months ago

Class 12th Wave Optics

Two light beams of intensities 4I and 9I interfere on a screen. The phase difference between these beams on the screen at point A is zero and at point B is π. The difference of resultant intensities, at the point A and B, will be_________I.

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Vishal Baghel

Contributor-Level 10

$I_{A} = 9 l + 4 l + 2 \sqrt[]{9 l * 4 l} c o s 0 °$

$= 13 l + 12 l = 25 l$

$I_{B} = 9 l + 4 l + 2 \sqrt[]{9 l * 4 l} c o s π$

$= 13 l - 12 l = l$

$∴ I_{A} - I_{B} = 24 l$

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6 months ago

Class 12th Moving Charges and Magnetism

A closely wounded circular coil of radius 5cm produces a magnetic field of 37.68 * 10^-4 T at its centre. The current through the coil is_ A. [Given, number of turns in the coil is 100 and π = 3.14]

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Vishal Baghel

Contributor-Level 10

$B_{c e n t r e} = N \frac{μ_{0} i}{2 r}$

$\Rightarrow \frac{100 * 4 π * 1 0^{- 7} * i}{2 * 5 * 1 0^{- 2}} = 37.68 * 1 0^{- 4}$

$∴ i = \frac{37.68}{4 * 3.14} = 3 A$

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6 months ago

Class 12th Physics

The current I flowing through the given circuit will be_________A.

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Vishal Baghel

Contributor-Level 10

$i = \frac{v}{R_{N e t}} = \frac{6}{3} = 2 A$

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6 months ago

Class 12th Maths

The sum, of all real values of x for which $\frac{3 x^{2} - 9 x + 17}{x^{2} + 3 x + 10} = \frac{5 x^{2} - 7 x + 19}{3 x^{2} + 5 x + 12}$ is equal to…………….

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Vishal Baghel

Contributor-Level 10

$\frac{3 x^{2} - 9 x + 17}{x^{2} + 3 x + 10} = \frac{5 x^{2} - 7 x + 19}{3 x^{2} + 5 x + 12}$

$1 + \frac{2 x^{2} - 12 x + 7}{x^{2} + 3 x + 10} = 1 + \frac{2 x^{2} - 12 x + 7}{3 x^{2} + 5 x + 12}$

$(2 x^{2} - 12 x + 7) (\frac{1}{x^{2} + 3 x + 10} - \frac{1}{3 x^{2} + 5 x + 12}) = 0$

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