IGCSE Physics - Topic 2: Thermal Physics - Paper 2 MCQ

1

Which statement correctly describes particles in a liquid?

AThey are in fixed positions and vibrate BThey are close together but can move around each other CThey are far apart and move at high speed DThey are arranged in a regular lattice pattern

2

Pollen grains on the surface of water are seen through a microscope to move in a random zigzag pattern. This observation provides evidence for:

AWater being a poor conductor of heat BThe existence of water currents CThe random motion of water molecules that are too small to see DElectrical forces between pollen grains

3

A gas is enclosed in a container. Which statement about gas pressure is correct?

AGas pressure is caused by the weight of gas molecules settling at the bottom BGas pressure acts only on the bottom of the container CGas pressure is caused by gas molecules colliding with the walls of the container DGas pressure decreases when the temperature increases at constant volume

4

Which change of state occurs when a gas becomes a liquid?

AEvaporation BSublimation CMelting DCondensation

5

A student squeezes a closed syringe containing air. The air volume decreases. Using the kinetic particle model, the pressure increases because:

AThe air particles become smaller BThe air particles collide with each other more often CThe air particles have more space to move in DThe air particles hit the walls of the syringe more frequently in the smaller volume

6

On a humid day in Bangalore, wet clothes take longer to dry. Using the kinetic particle model, this is because:

AThe water in the clothes is heavier on humid days BWater molecules in the air prevent as many water molecules from escaping the clothes' surface CGravity increases on humid days DThe clothes absorb more water from the air

7

When a solid is heated and melts, the particles:

AStop moving completely BBreak free from their fixed positions and can now move around each other CMove apart to large distances DDecrease in size

8

Which statement about diffusion is correct?

ADiffusion happens fastest in solids BDiffusion is the movement of particles from a region of lower concentration to higher concentration CDiffusion occurs because particles move randomly from a region of higher concentration to a region of lower concentration DDiffusion only happens in gases

9

The smell of cooking spreads throughout a house more quickly when the kitchen is hot. This is because:

AHot air is heavier and pushes the smell down BThe smell particles move faster at higher temperatures, so diffusion is more rapid CCold air blocks the smell particles DThe food releases fewer smell particles when cold

10

A gas in a sealed container is heated. The volume stays constant. What happens to the pressure?

AIt decreases because particles expand BIt stays the same because volume is fixed CIt increases because particles move faster and hit the walls harder and more often DIt increases because new particles are created

11

Which description best represents the arrangement of particles in a gas?

AParticles touching in a regular pattern BParticles touching but in an irregular arrangement CParticles far apart and randomly distributed DParticles in pairs, evenly spaced

12

Smoke particles observed in Brownian motion are much larger than air molecules. The smoke particles move randomly because:

AThey are hit by unequal numbers of air molecules from different directions at any instant BThey repel each other magnetically CGravity pulls them in random directions DThey are charged and attracted to the walls

13

What is 100 °C in kelvin?

A100 K B173 K C373 K D473 K

14

At absolute zero (0 K), which statement is correct?

AParticles are at maximum kinetic energy BParticles have minimum internal energy and motion virtually ceases CAll substances become gases DParticles vibrate at their maximum rate

15

A fixed mass of gas occupies 400 cm³ at 200 kPa. The pressure is increased to 400 kPa at constant temperature. What is the new volume?

A100 cm³ B200 cm³ C400 cm³ D800 cm³

16

Which temperature is equivalent to 0 K?

A0 °C B−100 °C C−273 °C D−373 °C

17

A gas syringe contains 80 cm³ of gas at 150 kPa. The plunger is pulled out until the pressure drops to 100 kPa, keeping temperature constant. What is the new volume?

A53 cm³ B80 cm³ C100 cm³ D120 cm³

18

The graph of pressure against 1/volume for a fixed mass of gas at constant temperature is:

AA curve BA horizontal line CA straight line through the origin DA straight line not through the origin

19

A student converts −50 °C to kelvin. The correct answer is:

A−50 K B50 K C223 K D323 K

20

A sealed gas jar is placed in a freezer. As the gas cools at constant volume, the pressure drops because:

AGas particles shrink in size BSome gas particles are destroyed CGas particles move more slowly and collide with the walls less forcefully and less often DThe glass jar contracts and pushes gas out

21

Railway tracks have small gaps between sections. These gaps are necessary because:

AThey reduce the cost of the railway BThey allow rain water to drain away CThey allow the tracks to expand in hot weather without buckling DThey make the train ride smoother

22

A glass bottle filled completely with water and sealed tightly is placed in a freezer. The bottle cracks. This happens because:

AGlass contracts more than water when cooled BWater expands when it freezes, exerting a force on the glass CThe freezer vibrates and cracks the glass DIce is heavier than water

23

Which statement about thermal expansion is correct?

ASolids expand more than gases for the same temperature rise BLiquids expand less than solids for the same temperature rise CGases expand the most for the same temperature rise DAll materials expand by the same amount

24

A student heats 3.0 kg of water from 25 °C to 75 °C. The specific heat capacity of water is 4200 J/(kg °C). How much energy is required?

A315 000 J B630 000 J C945 000 J D1 260 000 J

25

An electric heater supplies 13 500 J of energy to 0.5 kg of oil. The temperature of the oil rises by 15 °C. What is the specific heat capacity of the oil?

A450 J/(kg °C) B900 J/(kg °C) C1350 J/(kg °C) D1800 J/(kg °C)

26

Water has a high specific heat capacity. Which statement explains why coastal cities like Mumbai have more moderate temperatures than inland cities?

AThe sea reflects sunlight away from the coast BWater heats up and cools down slowly, moderating the temperature near the coast CCoastal cities have more trees DThe sea absorbs all radiation and prevents it reaching the land

27

A 0.2 kg piece of copper at 200 °C is dropped into 0.5 kg of water at 20 °C. The specific heat capacity of copper is 390 J/(kg °C) and water is 4200 J/(kg °C). Which statement about the final temperature is correct?

AIt will be exactly 110 °C (the average) BIt will be much closer to 20 °C than to 200 °C because water has a much higher heat capacity and mass CIt will be exactly 200 °C DIt will be exactly 20 °C

28

Two blocks of equal mass, one iron and one aluminium, are given the same amount of thermal energy. The aluminium block has a higher specific heat capacity than iron. Which block has the higher temperature rise?

AThe aluminium block BThe iron block CBoth have the same temperature rise DIt depends on their initial temperatures

29

During boiling, bubbles of vapour form throughout the liquid. During evaporation, particles escape only from the surface. Which other difference between boiling and evaporation is correct?

ABoiling occurs at any temperature; evaporation occurs at a fixed temperature BBoiling occurs at a specific temperature (the boiling point); evaporation can occur at any temperature below the boiling point CEvaporation is faster than boiling DBoiling does not require energy

30

After swimming in a pool, you feel cold when you step out into the breeze. This is mainly because:

AThe pool water was cold BThe wind blows cold air onto your body CWater evaporating from your skin removes thermal energy, cooling you down DYour body temperature drops when you leave the water

31

A substance is heated at a steady rate. The heating curve shows temperature rising, then a flat region, then temperature rising again. During the flat region:

AThe heater has been switched off BThe substance is cooling down CA change of state is occurring and energy is used to break intermolecular bonds DThe thermometer has reached its maximum reading

32

Which combination of factors increases the rate of evaporation?

ALower temperature, higher humidity, smaller surface area BHigher temperature, lower humidity, larger surface area, air movement across the surface CHigher pressure, higher humidity, no air movement DLower temperature, larger surface area, no air movement

33

Ice at 0 °C is placed in a glass of water at 0 °C. What happens?

AThe ice melts immediately BThe water freezes immediately CNeither melting nor freezing occurs because there is no temperature difference and therefore no net energy transfer DThe ice sinks to the bottom and melts

34

A copper-bottomed pan is used for cooking. Copper is chosen for the base because:

ACopper is shiny and looks attractive BCopper is a very good conductor of heat and transfers thermal energy quickly to the food CCopper is the cheapest metal available DCopper has a high specific heat capacity

35

Convection can occur in liquids and gases but not in solids because:

ASolids are too hot for convection BSolids are transparent to heat CIn solids, particles are in fixed positions and cannot flow to create convection currents DSolids do not absorb thermal energy

36

A Leslie's cube has four different surfaces: shiny black, dull black, shiny silver, and dull white. It is filled with hot water. Which surface emits the most infrared radiation?

AShiny silver BShiny black CDull black DDull white

37

A thermos flask has silvered inner walls. This reduces heat transfer by:

AConduction BConvection CRadiation DEvaporation

38

The Earth's average temperature remains roughly constant because:

AThe Earth absorbs no radiation from the Sun BThe rate at which the Earth absorbs radiation from the Sun is approximately equal to the rate at which it emits radiation into space CThe atmosphere blocks all radiation from the Sun DThe Earth only emits radiation at night

39

A student investigates heat transfer by wrapping a hot beaker with different materials. Which combination best reduces heat loss?

AShiny foil (reduces radiation) and a layer of trapped air or foam (reduces conduction and convection) BBlack paper and a wet cloth CThin metal sheet only DTransparent plastic wrap only

40

In a house, a radiator heats a room mainly by:

ARadiation only BConduction through the air CConvection — the radiator heats air near it, the warm air rises and is replaced by cooler air, setting up a convection current DEvaporation of water from the radiator

Mock 2 Results - Thermal Physics

Topic 2: Thermal Physics - Mock 2

Cambridge IGCSE Physics 0625 - Paper 2 (Multiple Choice)