Match the following: List-1 List-2 A) Global warming B) Eutrophication C) Biomagnification D) Ozone depletion I) Mercury II) UV-B rays III) Methane IV) Algal blooms V) Terror of Bengal The correct match is:

A = III , B = IV , C = I , D = II

A = III , B = V , C = I , D = II

A = II , B = I , C = IV , D = III

A = V , B = IV , C = II , D = I

MEDIUM

Earn 100

Assertion: For an ideal gas, at constant temperature, the product of the pressure and volume is constant.

Reason: The mean square speed of the molecules is $\sqrt{\frac{3 k_{B} T}{m}}$ , $k_{B}$ = Boltzman's constant, m = mass of molecule.

50% studentsanswered this correctly

Important Questions on Heat and Thermodynamics

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

In an ideal gas at temperature T, the average force that a molecule applies on the walls of a closed container depends on

T a s T^{q}

. A good estimate for q is:

HARD

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

What is global warming? Discuss the cause and effect of global warming. What measures need to be taken to control global warming?

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

The molecules of a given mass of gas have RMS velocity of

200

m s^{- 1}

27^{o} C

and

1.0 \times 10^{5} N m^{- 2}

pressure. When the temperature and pressure of the gas are respectively,

127^{o} C

and

0.05 \times 10^{5} N m^{- 2}

, the r.m.s. velocity of its molecules in

m s^{- 1}

is:

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Two vessels separately contain two ideal gases

A

and

B

at the same temperature, the pressure of

A

being twice that of

B

. Under such conditions, the density of

A

is found to be

1.5

times the density of

B

. The ratio of molecular weights of

A

and

B

HARD

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Match the following:

List-1	List-2
A) Global warming B) Eutrophication C) Biomagnification D) Ozone depletion	I) Mercury II) UV-B rays III) Methane IV) Algal blooms V) Terror of Bengal

The correct match is:

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

A spring - block system is resting on a frictionless floor as shown in the figure. The spring constant is

2.0 N m^{- 1}

and the mass of the block is

2 .0 kg

. Ignore the mass of the spring. Initially the spring is in an unstretched condition. Another block of mass

1.0 kg

moving with a speed of

2 .0 m s^{- 1}

collides elastically with the first block. The collision is such that the

2.0 kg

block does not hit the wall. The distance, in metres, between the two blocks when the spring returns to its unstretched position for the first time after the collision is _________.

Question Image

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Write any one reason for global warming.

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

10^{22}

gas molecules each of mass

10^{- 26}

kg collides with a surface (perpendicular to it) elastically per second over an area

1 m^{2}

with a speed

10^{4} m / s,

the pressure exerted by the gas molecules will be of the order of:

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

In the kinetic theory of gases, it is assumed that the gas molecules:

HARD

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

If the masses of all molecules of a gas are halved and their speeds doubled, then the ratio of initial and final pressure will be

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

The temperature of an ideal gas is increased from

100 K

400 K

. If the

r m s

speed of the gas molecule is

V

100 K

, then at

400 K

it becomes

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Two gases - argon (atomic radius

0.07 n m,

atomic weight

40

) and xenon (atomic radius

0.1 n m,

atomic weight

140

) have the same number density and are at the same temperature. The ratio of their respective mean free times is closest to:

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Which of the following shows the correct relationship between the pressure

' P'

and density

ρ

of an ideal gas at constant temperature ?

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

15 g

mass of nitrogen gas is enclosed in a vessel at a temperature,

27^{o} C

. The amount of heat transferred to the gas, so that

R . M . S .

velocity of molecules is doubled, is about.

[R = 8 .3 J {(K mole)}^{- 1}]

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Increase in temperature of a gas filled in a container will lead to

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

25 \times 10^{- 3} m^{3}

volume cylinder is filled with

1

mol of

O_{2}

gas at room temperature

(300 K)

. The molecular diameter of

O_{2}

, and its root mean square speed, are found to be

0.3 n m

and

200 m s^{- 1}

, respectively. What is the average collision rate (per second) for an

O_{2}

molecule?

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

The temperature, at which the root mean square velocity of hydrogen molecules equals their escape their escape velocity from the earth, is closest to:

[

Boltzmann Constant

k_{B} = 1.38 \times 10^{- 23} J / K

Avogadro number

N_{A} = 6.02 \times 10^{26} / k g

Radius of Earth:

6.4 \times 10^{6} m

Gravitational acceleration on Earth

= 10 m s^{- 2}]

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

What is global warming? Give any two causes responsible for global warming.

MEDIUM

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

Match the following

	LIST-I		LIST-II
A	Radioactive wastes	I	Global warming
B	Greenhouse effect	II	Snow blindness
C	UV — B rays	III	Biomagnification
D	DDT	IV	Mutations
		V	Eutrophication

The correct match is

EASY

Physics>Heat and Thermodynamics>Heat and Thermodynamics>Thermal Equilibrium and Temperature

N molecules each of mass m of a gas

A

and

2 N

molecules each of mass

2 m

of gas

B

are contained in the same vessel which is maintained at temperature

T

. The mean square velocity of molecules of

B

type is

v^{2}

and the mean square rectangular component of the velocity of

A

type is denoted by

ω^{2}

. Then the value of

ω^{2} / v^{2}

is -

Assertion: For an ideal gas, at constant temperature, the product of the pressure and volume is constant. Reason: The mean square speed of the molecules is 3kBTm , kB = Boltzman's constant, m = mass of molecule.

Important Questions on Heat and Thermodynamics

Learn and Prepare for any exam you want !

Assertion: For an ideal gas, at constant temperature, the product of the pressure and volume is constant.

Reason: The mean square speed of the molecules is $\sqrt{\frac{3 k_{B} T}{m}}$ , $k_{B}$ = Boltzman's constant, m = mass of molecule.