When a gas in a thermally insulated cylinder is suddenly
compressed, the change of state is....When a gas in a thermally insulated cylinder is suddenly
compressed, the change of state is....
a ... adiabatic.
b ... isothermal.
c ... isobaric.
d ... isochoric.
Which one of the diagrams at right correctly represents
the directions of the energy transfers that take place in a heat
pump?
The graph
at right shows the variation with volume of the pressure of
a system.
The work done as the gas is taken from Q to P is....
a ... 500 kJ.
b ... 450 kJ.
c ... 300 kJ.
d ... zero.
When a gas is compressed adiabatically the work done on
the gas is....
a ... zero.
b ... less than the change in internal energy, but not zero.
c ... equal to the change in internal energy.
d ... greater than the change in internal energy.
The P-V below diagram shows two isotherms for a fixed mass
of ideal gas, at temperatures Tx and Ty.
Which one of the following is correct?
a Tx > Ty
b Tx < Ty
c Tx = Ty
d Temperatures cannot be compared from a P-V diagram alone.
A gas is taken through a cycle process A - B - C - A as
shown in the P-V
diagram.
The work done by the gas during one complete cycle is....
a ... 24 kJ.
b ... 12 kJ.
c ... 6 kJ.
d ... 4 kJ.
The energy absorbed by an ideal gas during an isothermal
expansion is equal to....
a .... the work done by the gas.
b ... the work done on the gas.
c ... The change in internal energy of the gas.
d ... zero.
An ideal gas is enclosed in a cylinder fitted with a piston
as shown below.
The cylinder walls are thermally conducting. The gas is compressed isothermally by pushing the piston in slowly.
For this process, the thermal energy exchanged with the surroundings will be....
a ... zero.
b ... less than the work done.
c ... equal to the work done.
d ... greater than the work done.
When the volume of a gas increases it does work.
The work done would be greatest for which one of the following processes.
a Isobaric
b Adiabatic
c Isothermal
d The work done would be the same for all of the above.
A system absorbs 70 Joules of thermal energy and in the
process does 40 Joules of work. The internal energy change is....
a ... 30 J
b ... 40 J
c ... 70 J
d ... 110 J
In a given time interval 1200 J of energy is extracted from
a refrigerator cabinet and 1800 J of energy is ejected to the
outside.
The coefficient of performance for the refrigerator is....
a ... 0.5
b ... 0.7
c ... 2
d ... 4
An ideal gas expands isothermally, absorbing a certain amount
of energy, Q, in the process. It then returns to its original
volume adiabatically. During the adiabatic process the internal
energy change of the gas will be....
a ... zero.
b ... smaller than Q.
c ... equal to Q.
d ... greater than Q.
A gas is enclosed in a cylinder by means of a freely moving
piston. If the gas undergoes an adiabatic expansion which one
of the following statements is correct?
a The temperature of the gas remains constant.
b The pressure of the gas remains constant.
c Energy is transferred to the gas from the surroundings.
d The internal energy of the gas will decrease.