Short Type Questions On Class 11 Physics Chapter 12 Thermodynamics

1 A gas expands from 1 litre to 3 litre at atmospheric pressure. The work done by the gas is about

A 200 J

B 2 J

C 300 J

D 400 j

Answer:200 J

2 A uniform metal rod is used as a bas pendulum. If the room temperature rises by 10C and the efficient of line as expansion of the metal of the rod is, 2×10^-6 0^-1 Cwhat will have percentage increase in the period of the pendulum ?

A -2×10^-3

B 1×10^-3

C -1×10^-3

D 2×10^-3

View Answer

Answer:1×10^-3

3 A Centigrade and a Fahrenheit thermometers are dipped in boiling water-The water temperature is lowered until the Fahrenheit thermometers registered 140 what is the fall in thermometers

A 80

B 60

C 40

D 30

View Answer

Answer:40

4 The temperature of a body on Kelvin Scale is found to be x.K. when it is measured by Fahrenheit thermometers. it is found to be xF, then the value of x is .

A 313

B 301.24

C 574-25

D 40

View Answer

Answer:574-25

5 The temperature on Celsius scale is 25 C What is the corresponding temperature on the Fahrenheit Scale?

A 40 F

B 45 F

C 50 F

D 77 F

View Answer

Answer:77 F

6 At Which temperature the density of water is maximum?

A 4 F

B 42 F

C 32 F

D 39.2 F

View Answer

Answer:39.2 F

7 The temperature of a substance increases by 27°C What is the value of this increase of Kelvin scale?

A 30K

B 2-46K

C 7 K

D 27 K

View Answer

Answer:27 K

8 A gas mixture consists of 2 mde of oxygen and 4 mole of argon at tempressure T.Neglecting all vibrational modes, the total internal energy of the system is

A 11 RT

B 9 RT

C 15 RT

D 4 RT

View Answer

Answer:11 RT

9 One mole of a monoatomic gas is heate at a constant pressure of 1 atmosphere from 0k to 100 k. If the gas constant R = 8.32 J/mol k the change in internal energy of the gas is approximate ?

A 23 J

B 1.25×10³ J

C 8.67× 10³ J

D 46 J

View Answer

Answer:46 J

10 One mole of a monoatomic ideal gas is mixed with one mole of a diatomic ideal gas The molas specific heat of the micture at constant volume is ____

A 4 R

B 3 R

C R

D 2R

View Answer

Answer:2R

11 If du represents the increase in internal energy of a thesmodynamic system and dw the work done by the system, which of the following statement is true ?

A du = dw in isothermal process

B du = dw in aidabadic process

C du = - dw in an aidabadic process

D da = - dw in an isothermal process

View Answer

Answer:du = - dw in an aidabadic process

12 An engine is supposed to operate between two reservoirs at temperature 727°C and 227°C. The maximum possible efficiency of such an engine is

A 3/4

B 1/4

C 1/2

D 1

View Answer

Answer:1/2

13 An ideal refrigerator has a freetes at a temperature of -13°C, The coefficent of perfomance of the engine is 5. The temperature of the air to which heat is rejected will be.

A 325°C

B 39°C

C 325 K

D 320°C

View Answer

Answer:39°C

14 An ideal heat engine working between temperature T₁ and T₂ has an efficiency n. The new efficiency if both the source and sink temperature are doubled, will be

A n

B 2n

C 3n

D n/2

View Answer

Answer:n

15 For which combination of working temperatures the efficiency of Car not's engine is highest.

A 80 K, 60 K

B 100 K, 80 K

C 60 K, 40 K

D 40 K, 20 K

View Answer

Answer:40 K, 20 K

16 A car not engine takes 3×10⁶ cal of heat from a reservoir at 627°C , and gives to a sink at 27°C. The work done by the engine is

A 4.2×10⁶ J

B 16.8×10⁶ J

C 8.4×10⁶ J

D Zero

View Answer

Answer:8.4×10⁶ J

17 Efficiency of a car not engine is 50%, when temperature of outlet is 500K. in order to increase efficiency up to 60% keeping temperature of intake the same what is temperature of out let.

A 200 K

B 400 K

C 600 K

D 800 K

View Answer