Recent questions tagged class12

In a YDSE with $d= 1mm$ and $D= 1m$ slabs of $(t= 1 \mu m , \mu =3)$ and $(t=0.5\;\mu m , \mu =2) $ are introduced in front of upper and lower slit respectively . Then the shift in fringe pattern is :-

asked Feb 13, 2014 by meena.p

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The current through the battery is

asked Feb 13, 2014 by thanvigandhi_1

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White light is used in a YDSE with $D= 1m$ and $d= 0.9 mm$ .Light reaching the screen at position $y= 1 mm$ is passed through a prism and its spectrum is obtained. The missing lines in the visible region of this spectrum is :-

asked Feb 13, 2014 by meena.p

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The freezing point (in$^{\large\circ}C)$ of a solution containing 0.1g of $K_3[Fe(CN)_6]$ (mol .wt .329) in 100g of water $(K_t=1.86Kkgmol^{-1})$

asked Feb 13, 2014 by sreemathi.v

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Dissolving 120g of urea (mol.wt.60) in 1000g of water gave a solution of density 1.15g/ml.The molarity of solution is

asked Feb 13, 2014 by sreemathi.v

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Monochromatic light of wavelength $5000\;A^{\circ} $ is used in Y.D.S.E with slit- width $d= 1 mm$distance between screen and slits $D=1\;m$ Find the distance of 1000 th maxima

asked Feb 13, 2014 by meena.p

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The net resistance between the points A and B is

asked Feb 13, 2014 by thanvigandhi_1

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In the circuit shown in the figure, reading of the voltmeter is V1 when only S1 is closed, V2 when only S2 is closed and V3 when both S1 and S2 are closed. Then

asked Feb 13, 2014 by thanvigandhi_1

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For dilute solutions containing 2.5g of a non-volatile non electrolyte solute in 100g of water,the elevation in boiling point at 1atm pressure is $4^{\large\circ}C$.Assuming concentration of solute is much lower than the concentration of solvent,the vapour pressure (mm of Hg) of the solution is (take $K_b=0.76Kkgmol^{-1})$

asked Feb 13, 2014 by sreemathi.v

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Monochromatic light of wavelength $5000\;A^{\circ} $ is used in Y.D.S.E with slit- width $d= 1 mm$distance between screen and slits $D=1\;m$ .Then the distance of 5th minima from central maxima on screen is :-

asked Feb 13, 2014 by meena.p

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A particle of mass m and charge q is fastened to one end of a string of length l . The other end of the string is fixed to the point O . The whole system lies on a frictionless horizontal plane . Initially , the mass is at rest at A . A uniform electric field in the direction shown is the switched on . Then speed of the particle at B and tension in the string are

asked Feb 13, 2014 by yamini.v

1 answer

For dilute solutions containing 2.5g of a non-volatile non electrolyte solute in 100g of water,the elevation in boiling point at 1atm pressure is $2^{\large\circ}C$.Assuming concentration of solute is much lower than the concentration of solvent,the vapour pressure (mm of Hg) of the solution is (take $K_b=0.76Kkgmol^{-1})$

asked Feb 13, 2014 by sreemathi.v

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When no current passes through a conductor

asked Feb 13, 2014 by thanvigandhi_1

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Find the maxima and minima obtained on screen in a $YDSE, D= 1m,d=1mm$ and $ \lambda=\large\frac{1}{2}\;mm$

asked Feb 13, 2014 by meena.p

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Suppose you have three variable resistors each of range 15 ohms to 30 ohms. Which of the following values of equivalent resistance cannot be obtained using these 3 variable resistors?

asked Feb 13, 2014 by thanvigandhi_1

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A uniform wire of resistance $100\: ohms$ is cut into 10 equal parts and are connected in parallel to each other. The equivalent resistance of the combination is

asked Feb 13, 2014 by thanvigandhi_1

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98%(w/w) $H_2SO_4$ stock solution has a density of 1.8gm$L^{-1}$.The molecular weight of $H_2SO_4$ is 98g$mol^{-1}$.The volume(ml) of stock solution required to prepare a 1800ml of 1.0N $H_2SO_4$ is

asked Feb 13, 2014 by sreemathi.v

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The product of resistivity and conductivity of a conductor with uniform cross-section depends on

asked Feb 13, 2014 by thanvigandhi_1

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As the temperature of a metallic conductor is increased, the product of resistivity and conductivity

asked Feb 13, 2014 by thanvigandhi_1

2 answers

A current passes through a resistor. Let K1 and K2 be the average kinetic energy of the conduction electrons and metal ions respectively. Then:

asked Feb 13, 2014 by thanvigandhi_1

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Two resistors R and 2R are connected in series in a circuit. The thermal energy developed in R and 2R are in the ratio

asked Feb 13, 2014 by thanvigandhi_1

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Two resistors R and 2R are connected in parallel in a circuit. The thermal energy developed in R and 2R are in the ratio

asked Feb 13, 2014 by thanvigandhi_1

1 answer

29.2%(w/w) HCl stock solution has a density of 1.25g$ml^{-1}$.The molecular weight of HCl is 36.5$gmol^{-1}$.The volume (ml) of stock solution required to prepare a 500ml of 0.1M HCl is

asked Feb 13, 2014 by sreemathi.v

1 answer

In a YDSE, $D = 1m \; d= 1mm$ and $\lambda =\large\frac{1}{2}$$mm$ Then the distance between the first and central maxima on screen

asked Feb 13, 2014 by meena.p

1 answer

98%(w/w) $H_2SO_4$ stock solution has a density of 1.8g.m$L^{-1}$.The molecular weight of $H_2SO_4$ is 98g$mol^{-1}$.The volume (ml) of stock solution required to prepare a 450ml of 1.0M $H_2SO_4$ is

asked Feb 13, 2014 by sreemathi.v

1 answer

Consider the following two statements \[\] (A) Kirchhoff’s junction law follows from conservation of charge \[\] (B) Kirchhoff’s loop law follows from the conservative nature of electric field \[\] Then which of the following is true:

asked Feb 13, 2014 by thanvigandhi_1

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A charge q is placed at O in the cavity in a spherical uncharged conducter . Point S is outside the conducter . If q is displaced from O towards S (still remaining with in the cavity )

asked Feb 13, 2014 by yamini.v

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Two resistors A and B have their resistances $R_A\: and\: R_B$ with $R_A\: >\: R_B$. The resistivities of their material are related by

asked Feb 13, 2014 by thanvigandhi_1

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A metallic resistor is connected across a battery. If the number of collisions of free electrons with the lattice is somehow decreased in the resistor, the current will

asked Feb 13, 2014 by thanvigandhi_1

2 answers

Light from two sources , each of same frequency and travelling in same direction. but with intensity in ratio 4:1 interface. Find ratio of maximum to minimum intensity.

asked Feb 13, 2014 by meena.p

1 answer

98%(w/w) $H_2SO_4$ stock solution has a density of 1.8g.m$L^{-1}$.The molecular weight of $H_2SO_4$ is 98g$mol^{-1}$.The volume (ml) of stock solution required to prepare a 900ml of 0.5M $H_2SO_4$ is

asked Feb 13, 2014 by sreemathi.v

1 answer

In the circuit shown, potential difference between the points A and B is $16V$. The current passing through the $2\Omega$ resistor will be

asked Feb 13, 2014 by thanvigandhi_1

1 answer

$29.2\%$(w/w) $HCl$ stock solution has a density of $1.25gmL^{-1}$. The molecular weight of $HCl$ is $36.5g\;mol^{-1}.$ Find the volume $(ml)$ of stock solution required to prepare a $200\;ml$ of $0.4\;M\; HCl$ is

asked Feb 13, 2014 by sreemathi.v

1 answer

$S_1$ and $S_2$ are two sources of light which produce individually disturbance at a point P given by $\in _1=3 \sin wt,\;\in _2 =4 \cos wt$ Assuming $\overrightarrow {\in_1}$ and $\overrightarrow{\in_2}$ to be along the same line then result of their superposition is

asked Feb 13, 2014 by meena.p

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Current in the $3\: ohm$ resistor is

asked Feb 13, 2014 by thanvigandhi_1

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The equivalent resistance between the points A and B is:

asked Feb 13, 2014 by thanvigandhi_1

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A 5.0 molal aqueous solution of methyl alcohol,$CH_3OH$ is supplied.What is the mole fraction of methyl alcohol in the solution?

asked Feb 13, 2014 by sreemathi.v

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Ethylene glycol is used as an antifreeze in a cold climate.How much mass of ethylene glycol should be added to $5\;kg$ of water to prevent it form freezing at -$6^{\large\circ}C$ will be : $(K_t$ for water =$1.86Kkg mol^{-1}$ and molar mass of ethylene glycol=$62g mol^{-1})$

asked Feb 13, 2014 by sreemathi.v

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On mixing ,heptane and octane form an ideal solution.At 373K,the vapour pressures of the two liquid components (heptane and octane) are 105kPa and 45kPa respectively.Vapour pressure of the solution obtained by mixing 25g of heptane and 35g of octane will be (molar mass of heptane=100g $mol^{-1}$ and octane=114g$mol^{-1}$)

asked Feb 13, 2014 by sreemathi.v

1 answer

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, what is the change in freezing point of water$(\Delta T_f)$,when 0.02mol of sodium sulphate is dissolved in 1kg of water,is $(K_f=1.86Kkgmol^{-1})$?

asked Feb 13, 2014 by sreemathi.v

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A binary liquid solution is prepared by mixing n-heptane and ethanol.Which one of the following statements is correct regarding the behaviour of the solution?

asked Feb 13, 2014 by sreemathi.v

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If 200 mL of 0.1 M urea solution is mixed with 300 mL of 0.2 M Glucose solutions at 300 K calculate osmotic pressure.

asked Feb 13, 2014 by sreemathi.v

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The curve represents the distribution of potential along the straight line joining the two charges $\;Q_{1}\;$ and $\;Q_{2}\;$ (separated by a distance r ) then which of the following are correct 1. $\;|Q_{1}| > |Q_{2}|\;$ 2. $\;Q_{1}\;is\;+ve\;$ 3. $\;A\;$ and $\;B\;$ are equibrium points 4. $\;C\;$ is point of unstable equilibrium

asked Feb 13, 2014 by yamini.v

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Which of the following solutions will freeze at the lowest temperature?

asked Feb 13, 2014 by sreemathi.v

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Which of the following solution boils at the highest temperature?

asked Feb 13, 2014 by sreemathi.v

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Which of the following aqueous solutions posses zero as Van't Hoff coefficient?

asked Feb 13, 2014 by sreemathi.v

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The Van't Hoff factor of $BaCl_2$ is

asked Feb 13, 2014 by sreemathi.v

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Which one of the following solutions will have the lowest freezing point?

asked Feb 13, 2014 by sreemathi.v

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If $i= 3 \sin tw$ and $i_2= 4 \cos wt$ find $i_3$

asked Feb 13, 2014 by meena.p

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When a substance is dissolved in a solvent,the vapour pressure of the solvent is decreased.This result in

asked Feb 13, 2014 by sreemathi.v

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