A to Z Exams

Two cylindrical conductors A and B of same metallic material have their diameters in the ratio 1 : 2 and lengths in the ratio 2 : 1. If the temperature difference between their ends is same, the ratio of heats conducted respectively by A and B per sec is:

Two metal rods A and B of equal lengths and equal cross-sectional areas are joined end to end. The coefficients of thermal conductivities of A and B are in the ratio 2 : 3, when the free end of A is maintained at 1000C and the free end of B is maintained at 00C, the temperature of the junction is

A flask is filled with 1.3 g of an ideal gas at 270C and its temperature is raised to 520C The mass of the gas that has to be released to maintain the temperature of the gas in the flask at 520C and the pressure remaining the same is

A black body radiates energy at the rate of E watt/m2 at a high temperature T K. When the temperature is reduced to (T/2) K, the radiant energy is

The difference between heats of reaction at constant pressure and at constant volume for the reaction 2C6H6(l)+15O2(g) → 12CO2(g)+6H2O(l) at 250C in KJ is

An ideal gas is subjected to a cyclic process involving four thermodynamic states; the amounts of heat (Q) and work (W) involved in each of these states are

When a liquid is heated in copper vessel its Coefficient of apparent expansion is 6x10-6/0C.When the same liquid is heated in a steel vessel its coefficient of apparent expansion is 24x10-6/0C If coefficient of linear expansion for copper is 18x10-6/0C the coefficient of linear expansion for steel is

The temperature of 5 moles of a gas at constant volume is changed from 1000C to1200C The change In internal energy is 80J. The total heat capacity of the gas at constant volume will be in J/K is

A quantity of heat Q is supplied to a mono atomic ideal gas which expands at constant pressure. The fraction of heat that goes into work done by the gas is :

The tyre of a motor car contains air at 150C. If the temperature increases to 350C, the approximate percentage increase in pressure is (ignore to expansion of tyre)

Two gases A and B having same pressure P, volume V and absolute temperature T are mixed. If the mixture has the volume and temperature as V and T respectively, then the pressure of the mixture is

A tuning fork of frequency 392 Hz, resonates with 50 cm length of a string under tension T. If the length of the string is decreased by 2% keeping the tension constant the number of beats heard when the string and the tuning fork are made to vibrate simultaneously is :

If 9.8 gms of H2SO4 is neutralized exactly with strong alkali ,the heat evolved is(?H of neutralization is 13.6 K.cal)

A clock which keeps correct time at 200C, is subjected to 400C. If coefficient of linear expansion of the pendulum is 12x 10-6 /0C. How much will it gain or lose time

A piece of metal weighs 45gms in air and 25gms in a liquid  of density 1.5 X 103 kg-m-3 kept at 300 C . When the temperature of the liquid is raised to 400 C the metal piece weighs 27gms . The density of the liquid at 400 C is 1.25 X 103 kg-m-3 . The coefficient of linear expansion of metal is

In a chemical reaction, ΔH=150KJ and ΔS=100JK-1 at 300K. ΔG would be

The liquids at temperature 600C and 300C respectively have masses in the ratio 3 : 4 and their specific heats in the ratio 4 : 5. If the two liquids are mixed, the resultant temperature is:

The temperature of a thin uniform circular disc, of one metre diameter is increased by 100C. The percentage increase in moment of inertia of the disc about an axis passing through its centre and perpendicular to the circular face : (linear coefficient of expansion = 11 x l0-6/ 0C )

An electron remains undeflected when passing perpendicular to mutually perpendicular electric and magnetic fields. If the magnetic field is 8 Gauss and the electric field is 400 V/m, the velocity of the electron is:

A liquid of mass m and specific heat S is heated to a temperature T. Another liquid of mass mil and specific heat 2 S is heated to temperature 2 T. If these two liquids are mixed, the resultant temperature of the mixture :

The temperature of the system decreases in the process of

The relation between the coefficient of real expansion (γr) and coefficient of apparent expansion (γa) of a liquid and the coefficient of linear expansion (αg) of the material of the container is

A liquid of mass ‘m’ and specific heat C is heated to a temperature 2T.Anither liquid of mass m/2 and specific heat 2C is heated to a a temperature T.If these two liquids are mixed,the resulting temperature of mixture is

A wooden block is dropped from the top of a cliff 100m high.Simultaneously a bullet of mass 10g is fired from the foor of the cliff upwards with a velocity of 100 m/s.The bullet and wooden block will meet each other after a time:

In a compensated pendulum two rods of  different metals are used with their lengths in ratio of 2 : 3. The coefficients of linear expansions for metals in the ratio is :

The radiation emitted by a star A is 10,000 times that of the sun. If the surface temperatures of the sun and the star A are 6000 K and 2000 K respectively, the ratio of the radii of the star A and the sun is:

The difference between volume and pressure coefficients of an ideal gas is :

Power radiated by a black body at temperature T1 is P and it radiates maximum energy at a wavelength λ1.If the temperature of the black body is changed from T1toT2,it radiates maximum energy at a wavelength λ1/2.The power radiated at T2 is

When a liquid in a glass vessel, is heated its apparent expansion is 10.30 x 10-4same liquid when heated in a metal its apparent expansion 10.06 x 10-4/0C. The coefficient of linear expansion of the metal is : (coefficient of linear expansion of glass = 9 x 10-6/0C):

If 4 moles of an Ideal monoatomic gas at temperature 400 K is mixed with 2 moles of another ideal monoatomic gas at temperature 700 K, the temperature of the mixture is: