Higher Still Multiple Choice

1
Higher Still Multiple Choice

• Mechanics 1.3 Pressure and Gases

2
1. A rectangular block of wood of mass 200 kg has
dimensions of 2 m by 1 m by 0.1 m. The greatest
pressure which the block can exert when lying on
a flat level surface is

• 1 x 10 2 Pa
• 1 x 10 3 Pa
• 2 x 10 3 Pa
• 1 x 10 4 Pa
• 2 x 10 4 Pa

3
A solid cylinder of mass 20 kg has a flat base of
area 0.1 m 2 in contact with the level table on
which it rests. The pressure exerted on the table
by the cylinder resting in the position shown is

• 2 Pa
• 20 Pa
• 200 Pa
• 2000 Pa
• 20000 Pa

4
A vessel of cross-sectional area A contains a
liquid of density ? . At point X, a distance h
below the surface, the pressure due to the liquid
is

• ? g / A
• ? h
• hg / A
• ? h / g
• ? hg

5
A flat-bottomed can of weight 5 N floats with its
bottom 0.10 m below the surface of a liquid of
density 1.0 x 10 3 kg m -3 . If it is to float at
the same depth in a liquid of density 1.2 x 10 3
kg m -3 , a weight of

• 1.0 N should be added
• 1.0 N should be removed
• 0.83 N should be added
• 0.83 N should be removed
• 0.60 N should be added

6
Five liquids of different density are contained
in separate, identical tubes. The density of each
liquid is given in the diagram. In which tube is
the pressure greatest at point X?

7
The glass beaker shown below contains a liquid of
density ? and surface area A.Which of the
following is/are true about the pressure, caused
by the liquid, at depth d below the surface? I
The pressure varies directly as the surface area
A. II The pressure varies directly as the liquid
density ? . III The pressure varies inversely as
the depth d.

• I only
• II only
• III only
• I and II only
• II and III only

8
The low density of gases is best explained by

• low speed of gas molecules
• wide spacing between gas molecules
• small diameter of gas molecules
• small mass of gas molecules
• large volume of gas molecules

9
When a substance changes from liquid to gas at
atmospheric pressure, its density changes by a
factor of

• 10 -5
• 10 -4
• 10 -3
• 10 -2
• 10 -1

10
Which of the following gives the approximate
spacing of molecules in solid, liquid and gaseous
states of water? The molecular spacing in the
solid is d.
Solid Liquid Water Ice Water
Vapour

• d d 10d
• d 3d d
• d 3d 3d
• d 10d 10d
• d d 1000d

11
A fixed mass of gas condenses at atmospheric
pressure to form a liquid. By how much does its
density increase and by how much does the spacing
between its molecules decrease?
Approximate Approximate
increase in decrease
in density
spacing between molecules

• 10 times 2 times
• 100 times 10 times
• 1000 times 10 times
• 1000000 times 100 times
• 1000000 times 1000 times

12
A sample of oxygen gas at room temperature and
atmospheric pressure occupies a volume of 1 x 10
5 litres. The temperature and pressure are now
altered until all the gas has been liquefied. The
volume of liquid oxygen produced is approximately

• 1 x 10 2 litres
• 1 x 10 3 litres
• 1 x 10 4 litres
• 1 x 10 5 litres
• 1 x 10 6 litres

13
At standard temperature and pressure,
approximately what volume of gaseous carbon
dioxide would be formed from 1 cm3 of solid
carbon dioxide?

• 10 cm3
• 10 2 cm3
• 10 3 cm3
• 10 4 cm3
• 10 5 cm3

14
If p is the pressure of a gas and V is its
volume, in what unit could the quantity pV be
measured?

• newton
• watt
• newton metre -1
• newton second
• joule

15
In a gas, which physical quantity, averaged over
all the molecules, is directly proportional to
the Kelvin temperature of the gas?

• Mass
• Speed
• Weight
• Momentum
• Kinetic Energy

16
The Kelvin temperature of a gas varies directly as

• the average momentum of the molecules
• the average inertia of the molecules
• the average velocity of the molecules
• the average kinetic energy of the molecules
• the average potential energy of the molecules

17
A temperature - 20C is equivalent to

• 353 K
• 293 K
• 253 K
• 20 K
• -253 K

18
A liquid is heated from 17C to 50C. The
temperature rise, on the Kelvin scale is

• 33 K
• 67 K
• 306 K
• 340 K
• 579 K

19
Which of the following is not consistent with the
kinetic theory of an ideal gas?

• The molecules occupy a small fraction of the
  volume of the container
• The molecules collide inelastically
• The temperature gives a measure of the average
  kinetic energy of the molecules
• The gas pressure is due to molecular collisions
• The attractive forces between the molecules are
  negligible.

20
The kinetic theory idea of temperature of a body
is that it

• measures the degree of randomness of the motion
  of the particles
• is equal to the average momentum of the particles
  
• is equal to the average speed of the particles
• is related to the average kinetic energy of the
  particles
• is equal to the total kinetic energy of the
  particles.

21
The pressure of a gas can be affected by factors
such as its mass, its density, its volume and its
temperature. Pressure is inversely proportional
to volume if

• mass alone is constant
• density alone is constant
• temperature alone is constant
• mass and density alone are constant
• mass and temperature alone are constant.

22
The pressure on a fixed mass of a gas is doubled
at the same time that its Kelvin temperature is
doubled. Its volume will now be

• one quarter as great
• half as great
• the same as before
• twice as great
• four times as great.

23
A sealed container of gas is heated from 300 K to
600 K. What is the effect on the molecules of the
gas?

• the average speed is quadrupled
• the average kinetic energy is quadrupled
• the average speed is doubled
• the average momentum is doubled
• the average kinetic energy is doubled

24
During an experiment involving a fixed mass of
gas, the Kelvin temperature is trebled and the
volume is doubled. Due to these changes, the
pressure of the gas is

• 1/4 of its original value
• 2/3 of its original value
• 1 1/2 times its original value
• 1 2/3 times its original value
• 6 times its original value.

25
The volume of a certain mass of air at 27C is 3
m3 . If the temperature is increased to 127C
without changing the pressure, the new volume of
the air will be

• 2 1/4 m3
• 3 m3
• 4 m3
• 13 m3
• 15 m3.

26
The pressure-volume graph describes the behaviour
of a constant mass of gas as it is heated. Which
of the diagrams below shows the corresponding
pressure-temperature graph? (Where pressure (P)
is in kPa and temperature (T) is in K).

27
The temperature of a trapped gas is altered,
keeping the pressure constant. Which graph
correctly represents the variation of volume with
temperature?

28
The graph showing the relationship between
pressure and volume for a fixed mass of ideal gas
when the temperature is kept constant is

29
Which of the following graphs shows the
relationship between the volume of an enclosed
mass of ideal gas and its temperature when the
pressure is kept constant?

30
Which of the following graphs illustrates the
correct relationship between pressure P and
volume V for a fixed mass of gas at constant
temperature?

31
Gas in a cylinder is at room temperature and its
pressure is greater than atmospheric pressure.
Some of the gas is released into the atmosphere
and the cylinder is then resealed. What would a
graph of pressure (P)-volume (V) for the gas in
the cylinder look like while the gas is being
released?

32
Graphs X and Y show the pressure (P), volume (V)
and temperature (T) of a fixed mass of gas during
an experiment in which the gas starts with the
conditions shown at point 1 and undergoes changes
to the conditions shown at point 2.Which of the
following statements is/are correct? I The gas
expands according to Boyles Law (pressure-
volume law) II The gas is compressed at
constant temperature III The pressure decrease
at constant temperature.

• I only
• III only
• I and II only
• I and III only
• II and III only

33
A divers air cylinder has a capacity of 0.06 m3
. 4.0 m3 of air with a density of 1.44 kg m-3 is
compressed into it. What is the density of the
air in the cylinder?

• 0.02 kg m -3
• 0.17 kg m -3
• 5.76 kg m -3
• 6.00 kg m -3
• 96.0 kg m -3

34
The pressure gauge on an oxygen cylinder of
capacity 0.1 m3 reads 1.0 x 10 7 Pa. The density
of oxygen at atmospheric pressure (1.0 x 10 7 Pa)
is 1.4 kg m-3 . Assuming that the temperature
remains constant, what is the density of the
oxygen in the cylinder?

• 0.14 kg m -3
• 1.4 kg m -3
• 14 kg m -3
• 140 kg m -3
• 1400 kg m -3

35
After a car has been parked in the sun for some
time, it is found that the pressure in the tyres
has increased. This is because

• the volume occupied by the air molecules in the
  tyres has increased
• the force produced by the air molecules in the
  tyres acts over a smaller area
• the average spacing between the air molecules in
  the tyres has increased
• the increased temperature has made the air
  molecules in the tyres expand
• the air molecules in the tyres are moving with
  greater kinetic energy

36
Air is enclosed in a cylinder by a gas- tight
piston which can move freely in the cylinder. The
cross- sectional area of the piston is 3 x 10-3
m2. When the atmospheric pressure is 100 kPa, the
piston, when no force acts, settles 8 cm from the
end of the cylinder (fig. 1). It is then slowly
pulled out until it is 16 cm from the end of the
cylinder (fig. 2). Assuming no change in
temperature, the force F required to hold the
piston in this new position is

• 150 N
• 200 N
• 300 N
• 450 N
• 600 N

37
Flasks X, Y and Z have the same volumes. Y
contains air at a pressure of 600 kPa. X and Z
have been evacuated and the taps are closed. Tap
1 is now opened, followed a short time later by
Tap 2. Assuming that the temperature changes are
negligible, the pressures in kPa in flask Y
become respectively
Tap 1 open Tap 1 and 2 open

• 600 300
• 600 200
• 300 200
• 300 150
• 300 100

38
A rectangular box of mass 10 kg is lying on a
flat surface on a planet where the gravitational
field strength is 4 N kg -1 . The base of the box
measures 4 m by 2 m.Which of the following
statements is/are correct ? I The weight of the
box is 100 N. II The weight of the box is 40 N.
III The pressure which the box exerts on the
flat surface is 5 Pa.

• I only
• II only
• III only
• I and III only
• II and III only

39
The end of a bicycle pump is sealed with a small
rubber stopper. The air in chamber C is now
trapped. The plunger is then pushed in slowly,
causing the air in the chamber C to be
compressed. As a result of this, the pressure of
the air increases . Which of the following
explain(s) why the pressure increases, assuming
that the temperature remains constant? I The
air molecules increase their average speed . II
The air molecules are colliding more often with
the walls of the chamber. III Each air
molecule is striking the walls of the chamber
with greater force.

• II only
• III only
• I and II only
• I and III only
• E I, II and III

40
An aircraft cruises at an altitude at which the
air pressure is 0.4 x 10 5 Pa. The inside of the
aircraft cabin is maintained at a pressure of 1.0
x 10 5 Pa. The area of an external cabin door is
2 m 2 . What is the outward force produced on
this door by the pressures stated?

• 0.3 x 10 5 N
• 0.7 x 10 5 N
• 1.2 x 10 5 N
• 2.0 x 10 5 N
• 2.8 x 10 5 N

41
A small metal block is suspended from a spring
balance at a depth h below the surface of a
liquid in a large beaker. Which of the following
statements is/are true? I The reading on the
spring balance depends on the density of the
liquid in the beaker. II The reading on the
spring balance is equal to the upthrust of the
liquid on the metal block. III The reading on
the spring balance will increase as the depth h
is increased.

• I only
• II only
• III only
• I and II only
• I and III only

42
Which of the following gives the approximate
relative spacings of molecules in ice, water and
water vapour?
Molecular Molecular Molecular spacing
in spacing in spacing in water
ice/units water / units vapour/ units

• 1 1
  10
• 1 3
  1
• 1 3
  3
• 1 10
  10
• 3 1
  10

43
Which pair of graphs correctly shows how the
pressure produced by a liquid depends on the
depth and the density of the liquid?

44
A spacecraft of mass 1200 kg has landed on a
planet where the gravitational field strength is
5 N kg-l . The spacecraft rests on three pads,
each of contact area 0.5 m 2 . The pressure
exerted by these three pads on the surface of the
planet is

• 8.0 x 10 2 Pa
• 4.0 x 10 3 Pa
• 7.8 x 10 3 Pa
• 9.0 x 10 3 Pa
• 1.2 x 10 4 Pa.

45
A girl wrote the following statements in her
notebook. I The pressure of a fixed mass of gas
varies inversely as its volume, provided the
temperature of the gas remains constant. II The
pressure of a fixed mass of gas varies directly
as its kelvin temperature, provided the volume of
the gas remains constant. III A temperature
change of 20C in a gas is the same as a
temperature change of 293 K. Which of the above
statements is/are correct?

• I only
• II only
• III only
• I and II only
• II and III only

46
The pressure-volume graph below describes the
behaviour of a constant mass of gas when it is
heated. Which of the following shows the
corresponding pressure- temperature graph?

47
On a cold morning, a motorist checks the pressure
of the air in one of her car tyres. It is found
to be 3.0 x 10 5 Pa at a temperature of 2 C.
After a long run on a motorway, the temperature
of the air in the tyre rises to 57 C. The volume
of the air in the tyre remains constant and no
air escapes. Which row in the following table
gives the correct value of the final pressure of
the air in the tyre and a correct statement about
the final density of the air in the tyre compared
to the initial density?
Final pressure Final density of air
of air

• 8.6 x 10 6 Pa greater
• 8.6 x 10 6 Pa same
• 8.6 x 10 6 Pa less
• 3.6 x 10 6 Pa same
• 3.6 x 10 5 Pa less