Recent questions tagged 2014

An ideal monoatomic gas is confined in a cylinder by a spring loaded piston of cross section $\;8.0 \times 10^{-3}\;m^{2}\;$.Initially the gas is at 300K and occupies a volume of $\;2.4\times10^{-3}\;m^{3}\;$ and the spring is in its relaxed state as shown in figure.The gas is heated by a small heater until the piston moves out slowly by 0.1 m .The force constant of the spring is 800 N/m and the atmospheric pressure is $\;1.0 \times 10^{5}\;N/m^{2}\;$ . The cylinder and the piston are thermally insulated .The piston and the spring are massless and there is no friction between the piston and the cylinder .The final temperature gas will be : (Neglect the heat loss through the lead wires of the heater.The heat capacity of the heater coil is also negligible)

asked May 20, 2014 by yamini.v

1 answer

During an adiabatic compression , 830 J of work is done on 2 moles of a diatomic ideal gas to reduce its volume by $\;50\%\;$.The change in its temperature is nearly : $\;(R=8.3JK^{-1}mol^{-1})\;$

asked May 20, 2014 by yamini.v

1 answer

A hot body , obeying Newton's law of cooling is cooling down from its peak value $\;80^{0}C\;$to an ambient temperature of $\;30^{0}C\;$ . It takes 5 minutes in cooling down from $\;80^{0}C\;$ to $\;40^{0}C\;$. How much time will it take to cool down from $\;62^{0}C\;$ to $\;32^{0}C\;$ ? (Given ln 2=0.693 ; ln 5=1.609)

asked May 20, 2014 by yamini.v

1 answer

An air bubble of radius 0.1 cm is in a liquid having surface tension 0.06 N/m and density $\;10^{3}\;kg/m^{3}\;$ . The pressure inside the bubble is $\;1100\;Nm^{-2}\;$ greater than the atmospheric pressure . At what depth is the bubble below the surface of the liquid ? $\;(g=9.8)\;ms^{-2}\;$

asked May 19, 2014 by yamini.v

0 answers

A tank with a small hole at the bottom has been filled with water and kerosene (specific gravity 0.8) . The height of water is 3 m and that of kerosene 2 m . When the hole is opened the velocity of fluid coming out from it is nearly : (take $\;g=10\;ms^{-2}\;$ and density of water =$\;10^{3}\;kg\;m^{-3}\;$)

asked May 19, 2014 by yamini.v

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The bulk moduli of Ethanol , Mercury and water are given as 0.9 ,25 and 2.2 respectively in units of $\;10^{9}\;Nm^{-2}\;$ . For a given value of pressure , the fractional compression in volume is $\;\large\frac{ \bigtriangleup V}{V}\;$. Which of the following statements about $\;\large\frac{\bigtriangleup V}{V}\;$ for these three liquids is correct ?

asked May 19, 2014 by yamini.v

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From a sphere of mass M and radius R , a smaller sphere of radius $\;\large\frac{R}{2}\;$ is carved out such that the cavity made in the original sphere is between its centre and the periphery . (See figure) . For the configuration in the figure where the distance between the centre of the original sphere and the removed sphere is 3R , the gravitational force between the two spheres is :

asked May 19, 2014 by yamini.v

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A thin bar of length L has a mass per unit length $\;\lambda\;$ , that increases linearly with distance from one end .If its total mass is M and its mass per unit length at the lighter end is $\;\lambda_{0}\;$ , then the distance of the centre of mass from the lighter end is :

asked May 19, 2014 by yamini.v

1 answer

The average mass of rain drops is $\;3.0 \times 10^{-5}\;$ kg and their average terminal velocity is 9 m/s . Calculate the energy transferred by rain to each square metre of the surface at a place which receives 100 cm of rain in a year .

asked May 19, 2014 by yamini.v

0 answers

A small ball of mass m starts at a point A with speed $\;v_{0}\;$ and moves along a frictionless track AB as shown . The track BC has coefficient of friction $\;\mu\;$ . The ball comes to stop at C at travelling a distance L which is :

asked May 19, 2014 by yamini.v

1 answer

A body of mass 5 kg under the action of constant force $\;\overrightarrow{F}=F_{x} \hat{i} + F_{y} \hat{j}\;$ has velocity at t=0s as $\;\overrightarrow{v}=(6 \hat{i} -2 \hat{j})\;m/s\;$ and at t=10s as $\;\overrightarrow{v}=+6\hat{j}\; m/s\;$ . The force $\;\overrightarrow{F}\;$ is :

asked May 19, 2014 by yamini.v

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The initial speed of a bullet fired from a rifle is 630 m/s . The rifle is fired at the centre of a target 700 m away at the same level as the target . How far above the centre of the target the rifle must me aimed in order to hit the target ?

asked May 19, 2014 by yamini.v

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In terms of resistance R and time T , the dimensions of ratio $\;\large\frac{\mu}{\in}\;$ of the permeability $\;\mu\;$ and permittivity $\;\in\;$ is :

asked May 19, 2014 by yamini.v

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The gas liberated by the electrolysis of Dipotassium succinate solution is :

asked May 19, 2014 by yamini.v

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Which one of the following is used as Antihistamine ?

asked May 18, 2014 by yamini.v

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Tischenko reaction is a modification of :

asked May 18, 2014 by yamini.v

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In allene $\;(C_{3}H_{4})\;$ , the type(s) of hybridization of the carbon atom is (are) :

asked May 18, 2014 by yamini.v

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Complete reduction of benzene - diazonium chloride with $\;Zn/HCI\;$ gives :

asked May 18, 2014 by yamini.v

1 answer

Which one of the following does not have a pyramidal shape ?

asked May 18, 2014 by yamini.v

1 answer

Consider the coordination compound , $\;[CO(NH_{3})_{6}]Cl_{3}\;$ . In the information of this complex , the species which acts as the Lewis acid is :

asked May 18, 2014 by yamini.v

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Shapes of certain interhalogen compounds are stated below . Which one of them is not correctly stated ?

asked May 18, 2014 by yamini.v

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A gaseous compound of nitrogen and hydrogen contains $\;12.5\%\;$ (by mass) of hydrogen . The density of the compound relative to hydrogen is 16 . The molecular formula of the compound is :

asked May 18, 2014 by yamini.v

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Which of the following statements about the depletion of zone layer is correct ?

asked May 14, 2014 by yamini.v

1 answer

Which of the following statements about $\;Na_{2}O_{2}\;$ is not correct ?

asked May 14, 2014 by yamini.v

0 answers