The density of a substance at 0°C is 10 g/cc and at 100° C, its density is 9.7 g/cc. The coefficient of linear expansion of the substance is
10-4
102
10-3
102
A.
10-4
Initial temperature ( T1 ) = 0o C
Initial density ( ρ1 ) = 10 g/cc
Final temperature ( T2 ) = 100oC
Final density ( ρ2 ) = 9.7 g/cc
Coefficient of volumetric expansion
( ) =
=
=
=
v = 3 × 10-4
Therefore linear coefficient of linear expansion
1 =
=
1 = 10-4
The latent heat of vapourisation of water is 2240. If the work done in the process of vapourisation of 1 g is 168 J, then increase in internal energy is
2408 J
2072 J
2240 J
1904 J
An engine is working. It takes 100 calories of heat from source and leaves 80 calories of heat to sink. If the temperature of source is 127°C, then temperature of sink is
147°C
47°C
100°C
47 K
The heat produced in a long wire is characterized by resistance, current and time through which the current passes. If the errors in measuring these quantities are respectively 1 %, 2% and 1%, then the total error in calculating the energy produced is
4%
6%
4/3 %
8%
Anatomy 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