Question # 1

If the ratio of densities of two gases is 1:4, then the ratio of their rates of diffusion into one another is

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2 : 1

4 : 1

1 : 4

3 : 4

A typical four stroke petrol engine undergoes how many successive processes in each cycle

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one

two

three

four

In a heat engine, heat is supplied by the

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cold reservoir

sink

hot reservoir

none of them

Generally a temperature scale is established by using certain physical properties of a material which varies

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nonlinearly with temperature

linearly with temperature

either of them

none of them

In case of an ideal gas, the P.E associated with its molecule is

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maximum

zero

minimum

not fixed

The state in which ice, water and vapour coexists in equilibrium is called

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zero degree celsius

zero degree fahrenheit

absolute zero

373 K

If water in a closed bottle is taken up to the moon and opened, the water gets

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Freeze

Boiled

Dissociated into O₂and H₂

Evaporated

If a process cannot be retraced in the backward direction by reversing the controlling factors, it is

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a reversible process

an irreversible process

any one of them

both of them

On the exaust stroke, the outlet values opens. The residual gases are expelled and piston moves

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outwards

inwards

in either way

none of these

If a molecule with momentum mv strikes a wall and rebound then the change in momentum will be:

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-2 mv

Zero

2 mv

mv

At the constant temperature, if the value of a given mass of a gas is double, then the density of gas becomes:

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Double

Remains constant

Half

None of these

The efficiency of carnot engine cannot be 100% or one unless cold reservoir is at

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100 K

273 K

0 K

-273 K

The heat required to raise the temperature of one mole of the substance through 1 K is called

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heat capacity

specific heat capacity

molar specific heat

all of them

R.M.S velocity of a particle is V at pressure P. If pressure increases by two times, then R.M.S velocity becomes

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2V

3V

0.5V

V

Which of the following is a state variable

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entropy

pressure

volume

all of them

The temperature of gas is produced by

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At potential energy of its molecules

The kinetic energy of its molecules

The attractive force between its molecules

The repulsive force between its molecules

A carnot cycle consists of

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One step

two step

three steps

four steps

If R is gas constant for 1 gram mole, C_pand C_vare specific heat for a solid then

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C_p- C_v= R

C_p- C_{v < R}

C_p- C_{v = 0}

C_p- C_{v > R}

If a system undergoes a natural process it will go in the direction that causes the entropy of the system plus the environment to increase, this is another statement of

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second law thermodynamics

first law of thermodynamics

third law of thermodynamics

none of them

The efficiency of diesel engine is

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25%

25 - 30%

35%

35 - 40%

In the formula P = N₀KT, N₀denotes:

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Number of molecules per unit per volume

Number of moles

Number of molecules

None of these

10 c.c. each of oxygen and hydrogen are kept in separate flasks. Then which of the following relations is correct?

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Each have same number of molecules

Don't have same number of molecules

Can't be predicted

None

The product of the pressure and volume of an ideal gas is

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A constant

Approximately equal to the universal gas constant

Directly proportional to its temperature

Inversely proportional to its temperature

In the reverse process, the working substance passes through the same stages as in the direct process and

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thermal effects at each stage are exactly reversed

mechanical effects at each stage are exactly reversed

thermal and mechanical effects at each stage remain the same

thermal and mechanical effects at each stage are exactly reversed

The heat required to raise the temperature of one mole of the gas through 1 K at constant volume is called

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heat capacity

specific heat capacity

molar specific heat

molar specific heat at constant volume

If the distance between two charges is doubled, the force between them will become:

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Double

Half

Three times

One fourth

One third

The concept of entropy was introduced into the study of thermodynamics in

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1856

1865

1656

1685

Carnot heat engine only used

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isothermal processes

adiabatic processes

both of them

none of them

Rate of diffusion is

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Faster in solids than in liquids and gases

Faster in liquids than in solids and gases

Equal to solids, liquids and gases

Faster in gases than in liquids and solids

In the study of thermodynamics, which gas is considered as the working substance

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real gas

ideal gas

any gas may be ideal or real

none of them

The motion of molecules in gases is:

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Orderly

Random

Circular

All of these

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