Recent questions in Class11

Two steel wire are hang from roof.Their length and radius are in the ratio 3 : 5 and 1 : 2 respectively.If the extension in first wire is 2mm,what is extension in other if force applied is in the ratio 2 : 3?

asked May 7, 2014 by sreemathi.v

1 answer

A mass of 1kg is attached to the end of a rubber string 25cm long having radius 2mm,which is rotating in horizontal plane in a radius of 28cm with 50rpm.What is young modulus of string in $N/m^2$

asked May 7, 2014 by sreemathi.v

1 answer

A wire of r=1cm consist of 1m steel and 2m copper respectively.Total extension when a force applied is 1mm.Find the force is $Y_{cu}=1.1\times 10^{11}N/m^2,Y_{steel}=2\times 10^{11}N/m^2$.

asked May 7, 2014 by sreemathi.v

1 answer

2 wire of length 1 : 2 and area in the ratio 2 : 1 is applied with equal force stretch equally .Find the ratio of modulus of rigidity

asked May 7, 2014 by sreemathi.v

1 answer

The breaking stress of aluminium is $7\times 10^7N/m^2$.Find the maximum length of wire that can be hang with out breaking if density of aluminium is $3\times 10^3Kgm^{-3}$

asked May 7, 2014 by sreemathi.v

1 answer

Calculate change in volume percentage if we apply a pressure of 50atm on a material of Bulk modulus $2\times 10^{11}N/m^2$.

asked May 7, 2014 by sreemathi.v

1 answer

If $Y_{Steel}=2\times 10^{11}N/m^2$ ,what force must be applied to steel rod of $l=2m$ and $r=2mm$ to stretch it by 1mm

asked May 7, 2014 by sreemathi.v

1 answer

Among rubber and steel which is more elastic

asked May 7, 2014 by sreemathi.v

1 answer

Each side of a cube is decreased by 2% when a pressure of $3\times 10^6N/m^2$ is applied.What is bulk modulus of cube.

asked May 7, 2014 by sreemathi.v

1 answer

A 50KN force is applied on a table,the length of four legs of table is 2m each and of radius 5cm.If young modulus of material of table is $5\times 10^{10}N/m^2$.Find the decrease in length in a leg of table.

asked May 7, 2014 by sreemathi.v

1 answer

A steel rod of r=30mm and length 3m.A 50 KN force is applied along its length.Calculate the change in length is $Y=2\times 10^{11}N/m^2$

asked May 7, 2014 by sreemathi.v

1 answer

A steel wire of 8m in length is stretched by 1mm of cross sectional area $2mmm^2$ .If young modulus of steel is $2\times 10^{11}N/m^2$.What is elastic potential energy?

asked May 7, 2014 by sreemathi.v

1 answer

A 3cm cube has its upper face displaced by 0.1cm by a tangential force.If modulus of rigidity of material is $5\times 10^4N/m^2$.Find the force

asked May 7, 2014 by sreemathi.v

1 answer

If 5litre of ideal gas is compressed isothermally at 800mm Hg to 2 litre.Find its stress?

asked May 7, 2014 by sreemathi.v

1 answer

If we increases the pressure by 20atm on a sphere which is made up of material of bulkmodulus $5.2\times 10^{10}N/m^2$,what is change in volume percentage?

asked May 7, 2014 by sreemathi.v

1 answer

Two wires of same material have radius in the ratio 2 : 1 and length in the ratio 1 : 2.If equal force is applied on them then ratio of stress is

asked May 7, 2014 by sreemathi.v

1 answer

A steel wire of l=15m and r=1mm is stretched by a unknown force F.If young modulus of steel wire is $2.4\times 10^{11}N/m^2$ and change in length is $5\times 10^{-2}mm$

asked May 7, 2014 by sreemathi.v

1 answer

Temperature of $4 mol$ of an ideal gas occupying $5 dm^3$ at $3.32\; bar \; (R= 0.083\;bar \;dm^3 K)$

asked May 2, 2014 by meena.p

1 answer

$4g$ of $O_2$ gas has pressure $P_0$ ad temperature $T_o$ i a vessel . On keeping the Sample at $50^{\circ}\;C$ higher temperature, $1g$ gas is given ad to maintain the original pressure $P_0$ . Then $T_0=?$

asked May 2, 2014 by meena.p

1 answer

The r ms speed of the molecules of a ideal gas which is at a pressure $10^5 \;m^{-2}$ & density $45\;kgm^{-3}$ is _________

asked May 2, 2014 by meena.p

1 answer

Boltzmann curve is given below :

asked May 2, 2014 by meena.p

1 answer

The reason why $Cp$ is greater than $Cv$ is _______

asked May 2, 2014 by meena.p

1 answer

The graph of PV v/s T is plotted for $Co_2,H_2$ and $N_2$ samples of equal masses Then the correct statement is

asked May 2, 2014 by meena.p

1 answer

Which one of the graphs below best illustrates the relationship between internal energy U and temperature T of the gas in K ?

asked Apr 22, 2014 by yamini.v

1 answer

$\;C_{p}\;$ and $\;C_{v}\;$ denote the molar specific heat capacities of a gas at constant pressure and constant volume respectively . Then

asked Apr 22, 2014 by yamini.v

1 answer

An ideal gas initially at a state $\;(P_{1},V_{1})\;$ is allowed to expand isothermally to a state $\;(P_{2},V_{2})\;$ . Then the gas is compressed adiabatically to its initial volume $\;V_{1}\;$ . Let the final pressure be $\;p_{3}\;$ and the workdone by the gas be W , Then

asked Apr 9, 2014 by yamini.v

1 answer

A sample of an ideal gas is taken through the process ABCA shown . It rejects 50 J of heat during part AB , does not absorb or reflect heat during BC and accepts 70 J of heat during CA . Forty joules of work is done on the gas during the part BC . The internal energies at B and C respectively will be $\;(u_{A} =1500\;J)$

asked Apr 9, 2014 by yamini.v

1 answer

Logarithms of readings of pressure and volume from ideal gas were plotted on a graph as shown . By measuring the gradient , it can be shown that the gas may be

asked Apr 9, 2014 by yamini.v

1 answer

An ideal gas is filled in a closed rigid and thermally insulated container . A coil of 100 oms resistor carrying a current of 1 A for 5 minutes supplies heat to the gas . The change in the internal energy of the gas is

asked Apr 9, 2014 by yamini.v

1 answer

An ideal gas is taken through the cycle $\;A \to B \to C \to A \;$ as shown in the figure . If the net heat supplied to the gas in the cycle is 5 J , the work done by the gas is the process $\;C \to A\;$ is

asked Apr 9, 2014 by yamini.v

1 answer

Starting from the same initial conditions , an ideal gas expands from volume $\;V_{1}\;$ to $\;V_{2}\;$ in three different ways . The work done by the gas is $\;W_{1}\;$ if the process is purely isothermal , $\;W_{2}\;$ if purely isobaric and $\;W_{3}\;$ if purely adiabatic . Then :

asked Apr 9, 2014 by yamini.v

1 answer

A thermodynamics ideal gas , initially at temperature $\;T_{1}\;$ ia enclosed in a cylinder fitted with a friction less piston . The gas is allowed to expand adiabatically to a temperature $\;T_{2}\;$ by releasing the piston suddenly . If $\;L_{1}\;$ and $\;L_{2}\;$ are the lengths of gas column before and after expansion respectively , then $\;\large\frac{T_{1}}{T_{2}}\;$ is given by

asked Apr 9, 2014 by yamini.v

1 answer

A thermodynamic process , the pressures and volumes corresponding to some points in the figure are $\;P_{A} = 3 \times 10^{4}\;pa \;,V_{A} = 2 \times 10^{-3} \;m^3\;$ . $\;P_{B}=8 \times 10^{4}\;pa\;V_{D} = 5 \times 10^{-3}\;m^3\;$. In the process AB , 600 J of heat and in the process BC , 200 J of heat is added to the system . The change in internal energy in process AC would be

asked Apr 9, 2014 by yamini.v

1 answer

Volume $\;V_{S}\;$ Temperature graph of two moles of helium gas is show in figure . The ratio of heat absorbed and the work done by the gas in process 1 - 2 is

asked Apr 9, 2014 by yamini.v

1 answer

Which type of ideal gas will have the largest value for C$_P$-C$_V$?

asked Apr 8, 2014 by yamini.v

1 answer

A copper disc at $\;0^{0}C\;$ has a diameter of 50 cm and a hole is cut in the center with a diameter 5 cm . The diameter of the hole at $\;100^{0}C\;$ will be $\;(\alpha = 0.00016/^{0}C)\;$

asked Apr 8, 2014 by yamini.v

1 answer

A composite bar of length $\;(l_{1} + l_{2})\;$ is made from two bars of length $\;l_{1}\;$ and $\;l_{2}\;$ . Their coefficients of linear expansion $\;\alpha_{1}\;$ and $\;\alpha_{2}\;$ respectively . The effective linear coefficient of composite bar

asked Apr 8, 2014 by yamini.v

1 answer

When a block of iron floats in mercury at $\;0^{0}C\;$ , a fraction $\;K_{1}\;$ of its volume is submerged. While at the temperature $\;60^{0}C\;$ , a fraction $\;K_{2}\;$ is seen submerged . If the coefficient of volume expansion of iron is $\;r_{Fe}\;$ and that of mercury is $\;r_{Hg}\;$ , then the ratio $\;\large\frac{K_{1}}{K_{2}}\;$ can be expanded as

asked Apr 8, 2014 by yamini.v

1 answer

The apparent expansion of a liquid when heated in a copper vessel is C and when heated in a silver vessel is S . If A is coefficient of linear expansion of silver is

asked Apr 8, 2014 by yamini.v

1 answer

$\;l_{1}\;$ and $\;l_{2}\;$ are the lengths of two rods at $\;0^{0}C\;$ and have coefficients of linear expansion $\;\alpha_{1}\;$ and $\;\alpha_{2}\;$ respectively . If the difference between the lengths X is the same at all temperatures then $\;l_{1}\;$ is

asked Apr 8, 2014 by yamini.v

1 answer

A wire of length 60 cm is bent into a circle with a gap of 1 cm at its ends . On heating by by $\;100^{0}C\;$ , If the length of the gap increases to 1.02 cm , $\;\alpha\;$ of the material of the wire is

asked Apr 8, 2014 by yamini.v

1 answer

The brass scale of a barometer is correct at $\;0^{0}C\;$ and it reads 755 mm at $\;25^{0}C\;$ , Its reading at $\;0^{0}C\;$ is $\;r_{mercury} = 0.00018/^{0}C\;,r_{brass} =0.00021/^{0}C$

asked Apr 8, 2014 by yamini.v

1 answer

If the temperature of metal sphere increases by $\;\bigtriangleup t\;$ , the fractional change in its moment of inertia is $\;(\alpha \;= Coefficient\; of\; linear \;expansion )$

asked Apr 8, 2014 by yamini.v

1 answer

The wavelength $\;\lambda_{m}\;$ of maximum intensity of emission of solar radiation is $\;\lambda_{m}=14\; \mu m\;$. The surface temperatures of sun and moon are (given $ b= 2.898 \times 10^{-3} \; metre/Kelvin $).

asked Apr 8, 2014 by yamini.v

1 answer

A metal ball having surface area of $\;2 \times 10^{-2}\;m^2\;$ and at 900 K is kept in an enclosure at 300 K . If the surface emissivity of metal is 0.4 , find the rate of which heat is lost by the ball

asked Apr 8, 2014 by yamini.v

1 answer

A steel rod of length 20 cm and cross sectional area 3 $cm^{2}$ is heated at one end to $\;300^{0}C\;$ and the other end is in ice . Assuming no loss of heat , the mass of ice that melts in 10 minutes if $\;K_{steel} = 0.16 \;C.G.S\;$ units .

asked Apr 8, 2014 by yamini.v

1 answer

The temperature of a solid falls from $\;77^{0}C\;$ to $\;73^{0}C\;$ in 3 minutes and $\;73^{0}C\;$ to $\;69^{0}C\;$ in 4 minutes . What is the room temperature ?

asked Apr 8, 2014 by yamini.v

1 answer

The temperature of a solid falls from $\;72^{0}C\;$ to $\;60^{0}C\;$ in 10 minutes . How much time will it take to cool from $\;60^{0}C\;$ to $\;52^{0}C\;$ if the temperature of surroundings is $\;36^{0}C\;$ c ?

asked Apr 8, 2014 by yamini.v

1 answer

A copper rod AB of length 100 cm is fixed with a steel rod BC of length 20 cm at B . If the ends A and C are maintained at temperature $\;100^{0}C\;$ and $\;0^{0}C\;$ , then the temperature of the function B is : [thermal conductivities of copper and steel are 0.9 and 0.18 CGS units respectively ]

asked Mar 31, 2014 by yamini.v

1 answer

A cylinder of radius r and thermal conductivity $\;K_{1}\;$ is surrounded by cylindrical shell of inner radius r and outer radius 2r and thermal conductivity $\;K_{2}\;$ . The effective thermal conductivity when ends of combined system $\;t_{1}\;$ and $\;t_{2}\;$ under steady state is

asked Mar 31, 2014 by yamini.v

1 answer

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