CBSE
Multiple Choice QuestionsAnatomy and Bismuth are usually used in thermocouple, because
a constant e..m.f is produced
higher thermo e.m.f is produced
a negative e.m.f is produced
lower thermo e.m.f is produced
A Carnot engine takes heat from a reservoir at 627° C and rejects heat to a sink at 27° C. Its efficiency will be
3/5
1/3
2/3
200/209
A Carnot's engine operates with source at 127°C and sink at 27°C. If the source supplies· 40 kJ of heat energy, the work done by the engine is
30 kJ
10 kJ
4 kJ
1 kJ
The velocity of sound in air at NTP is 330 m/s. What will be its value when the temperature is doubled and pressure is halved?
330 m/s
165 m/s
330 m/s
Two gases A and B at same pressure contain a number of moles n1 and n2. Their volume temperature graphs are shown in the figure. Then the ratio n1/n2
1
1/2
1/3
3
The figure shows a P-V diagram. How does the work done in the process change with time?
First decreases and then increases
First increases and then decreases
Continuously decreases
Continuously increases
Which of the following parameters does not characterize the thermodynamic state of matter?
Volume
Temperature
Pressure
Work
At 27°C, a motor car tyre has a pressure of 2 atmospheres. The temperature at which the tyre suddenly burst will be : (Given: γair = 1.4)
246.1 K
250 K
246 K
248 K
In an isochoric process:
ΔV = 0
Δw = 0
Δa = 0
ΔT = 0
An ideal gas is taken through the cycle A ➔ B ➔ C ➔ A, as shown in the figure. If the net heat supplied to the gas in the cycle is 5J, the work done by the gas in the process. C ➔ A is :
-5 J
-10 J
-15 J
-20 J
