Physics for IGCSE & O level - Thermal Effects (Section 1)
1
Which type of surface is the best at reflecting thermal radiation and therefore appears cooler?
Απάντηση
(C)
Shiny
2
Which state of matter has a fixed shape?
Απάντηση
(A)
Solid
3
Which state of matter contains particles with the most kinetic energy?
Απάντηση
(C)
Gas
4
Which type of wave does the sun emit that we can feel as heat?
Απάντηση
(B)
Infrared waves
5
What causes the cooling effect experienced during evaporation?
Απάντηση
(A)
The faster particles escape from the liquid.
6
What happens to the volume of a gas when heated at a constant pressure?
Απάντηση
(A)
The volume increases.
7
What is a result of the convection of a hot water system?
Απάντηση
(C)
Cool water sinks and warm water rises
8
What happens to the particles of a solid when it is heated?
Απάντηση
(C)
They vibrate faster
9
What happens to the temperature during a change of state?
Απάντηση
(C)
The temperature remains constant
10
What is the term used to describe the change in state from a liquid to a gas?
Απάντηση
(C)
Vaporization
11
Why does a solid have a definite shape and volume?
Απάντηση
(D)
All of the above.
12
What happens to most substances when they are heated?
Απάντηση
(B)
They expand
13
What happens to the latent heat during melting?
Απάντηση
(B)
It is absorbed
14
What type of insulation is most commonly used to reduce heat loss from a house?
Απάντηση
(D)
All of the above
15
During the convection in a liquid, water rises upwards as a:
Απάντηση
(D)
hotter water
16
How does increasing the temperature of a gas affect the pressure, assuming the volume is constant?
Απάντηση
(B)
The pressure increases.
17
What is the name of the unit that measures the temperature?
Απάντηση
(C)
Celsius
18
Which color is a poor absorber of thermal radiation?
Απάντηση
(B)
White
19
What does the term 'absolute zero' represent?
Απάντηση
(C)
The temperature at which molecular motion stops.
20
Which statement is correct concerning the kinetic theory of matter?
Απάντηση
(C)
Particles in a gas move randomly and have little to no attraction to each other.
21
What is the effect of high specific heat capacity?
Απάντηση
(A)
Materials heat up and cool down slowly
22
What happens to the rate of evaporation if you increase the surface area?
Απάντηση
(B)
It increases
23
What is the process of heat transfer called that occurs in direct contact?
Απάντηση
(A)
Conduction
24
What does a thermocouple thermometer measure?
Απάντηση
(B)
The force generated between two dissimilar metals due to a temperature difference
25
Which is the formula for calculating energy transfer?
Απάντηση
(B)
Energy Transferred = mass * specific heat capacity * temperature change
26
What is the main difference between a solid, liquid, and gas in terms of particle arrangement and movement?
Απάντηση
(C)
Solids have a fixed arrangement with limited movement, liquids have a less ordered arrangement with more movement, and gases have a very random arrangement with fast movement.
27
Which factor is responsible for increasing the rate of evaporation?
Απάντηση
A
C
28
Which statement is correct about the specific latent heat of fusion?
Απάντηση
(B)
Energy is absorbed when a substance melts.
29
In a convection current, why does the warmer fluid rise?
Απάντηση
(A)
It is less dense.
30
How does the presence of clouds affect the Earth's temperature?
Απάντηση
(B)
They decrease the temperature by reflecting radiation
31
Why does a gas exert pressure on the walls of its container?
Απάντηση
(C)
Because the gas molecules are colliding with the walls.
32
Which method of heat transfer is most significant in the oceans, transferring heat from the equator towards the poles?
Απάντηση
(B)
Convection
33
Which of the following is a good thermal conductor?
Απάντηση
(C)
Metal
34
In the context of evaporation, which of the following factors reduces the rate of evaporation?
Απάντηση
(C)
Increasing the humidity
35
Which of the following explains why solids have a definite shape and volume?
Απάντηση
(A)
Particles are tightly packed and held together by strong forces
36
What does convection require to occur?
Απάντηση
(C)
A fluid
37
Which of the following is the correct unit for measuring the rate of heat transfer?
Απάντηση
(B)
Watt (W)
38
What type of surface is a poor reflector of thermal radiation?
Απάντηση
(A)
Black
39
What happens to the volume of a gas if its temperature decreases while keeping pressure constant?
Απάντηση
(B)
The volume decreases.
40
How does the specific heat capacity of a substance relate to its ability to store thermal energy?
Απάντηση
(A)
Directly proportional: higher heat capacity, more energy stored.
41
What is the name for the heat required to change the state of a substance from liquid to gas?
Απάντηση
(C)
Latent heat of vaporization
42
Which term is defined as the total internal energy of a substance?
Απάντηση
(C)
Internal energy
43
What is temperature?
Απάντηση
(B)
The average kinetic energy of the particles in a substance.
44
What is the transfer of energy by electromagnetic waves called?
Απάντηση
(C)
Radiation
45
What does latent heat cause during a state change?
Απάντηση
(C)
Temperature to remain constant.
46
What is the main reason for using insulating materials in the construction of buildings?
Απάντηση
(B)
To reduce heat transfer
47
What is the role of thermal radiation on the Earth?
Απάντηση
(A)
Heating up the Earth
48
Which of these materials is typically used in a bimetallic strip?
Απάντηση
(A)
Two different types of metal.
49
What is Brownian motion?
Απάντηση
(D)
The random movement of particles suspended in a fluid.
50
What is the name of the phenomenon describing the random movement of particles?
