CBSE
Multiple Choice QuestionsHelium at 270C has a volume 8 litres. it is suddenly compressed to a volume of 1 litre. The temperature of the gas will be
93270C
12000C
9270C
1080C
The volume (V) of a monatomic gas varies with its temperature (T), as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a change from state A to state B, is
2/5
2/3
2/7
1/3
A small sphere of radius 'r' falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to
r3
r2
r4
r5
Energy is being emitted from the surface of a black body at 127°C the rate of 1.0 x 106 J/sm2. The temperature of the black body at which the rate of energy emission is 16.0 x 10° J/sm2 will be
7540C
5270C
2540C
5080C
The temperature of source and sink of a heat engine are 127oC and 27oC, respectively. An inventor claims its efficiency to be 26%, then
It is impossible
It is possible with high probability
It is possible with low probability
Data are insufficient
p-V plots for two gases during the adiabatic process as shown in figure plots 1 and 2 should correspond respectively to
He and O2
O2 and He
He and Ar
O2 and N2
The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is
26.8%
20%
12.5%
6.25%
Carnot engine having an efficiency of 1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is
1 J
90 J
99 J
99 J
Air is expanded from 50 litres to 150 litres at atmosphere the external work done is (1 atmospheric pressure =1)
200J
2000J
A sample of 0.1 g of water at 100°C and normal pressure (1.013 × 105 Nm–2) requires 54 cal of heat energy to convert to steam at 100°C. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is
104.3 J
208.7 J
84.5 J
42.2 J
