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WorksheetsThermal physics
Total questions: 45
Worksheet time: 28mins
Energy transmitted by electromagnetic waves
conduction
convection
radiation
__________ is the transfer of heat by the movement of a fluid.
Conduction
Convection
Radiation
Which of the following best describes temperature?
Number of molecules
Motion of molecules
Size of molecules
Type of molecules
When two things are the same temperature:
They have the same number of molecules
Their molecules stop moving
Their molecules move at the same average speed
Heat transfer between the two things stops
Heat from the Sun reaches Earth through which type of heat transfer?
Conduction
Radiation
Convection
All of the above
Brooks is at recess in a sunny day. He drinks water from his water bottle, the water was hot. how'd the water get hot?
Conduction
Convection
radiation
all of the above
In an experiment, a metal rod is heated at one end. What happens to the heat?
It stays at the heated end
It moves to the cooler end
It dissipates into the air
It cools down immediately
What is thermal conductivity?
The rate at which particles move in a substance
The ability of a substance to have a large thermal energy
A factor that determines the amount of thermal energy of a substance
The rate at which a substance transfers heat
Thermal energy will always move __________.
wherever it is warm
toward the ground
from warm matter to cold matter
from cold matter to warm matter
What is the principle of bimetallic strip?
Two different metals with the same coefficient of thermal expansion are bonded together.
The principle of bimetallic strip is based on the use of only one type of metal.
A single metal with varying coefficient of thermal expansion is used.
Two different metals with different coefficients of thermal expansion are bonded together.
Name two common applications of bimetallic strips.
Refrigerators and cell phones
Cooking utensils and light bulbs
Thermostats and circuit breakers
Car engines and bicycles
How are bimetallic strips used in thermostats?
They emit heat based on temperature changes
They bend and complete or break an electrical circuit based on temperature changes.
They change color based on temperature changes
They expand and contract based on temperature changes
What is the principle of bimetallic strip?
Two different metals with the same coefficient of thermal expansion are bonded together.
The principle of bimetallic strip is based on the use of only one type of metal.
A single metal with varying coefficient of thermal expansion is used.
Two different metals with different coefficients of thermal expansion are bonded together.
Explain the working of a bimetallic strip based on its principle.
When heated, the bimetallic strip bends due to differential expansion of the two metals.
The bimetallic strip works by attracting magnetic fields
The bimetallic strip bends due to the force of gravity
When heated, the bimetallic strip remains straight
Name two common applications of bimetallic strips.
Refrigerators and cell phones
Cooking utensils and light bulbs
Thermostats and circuit breakers
Car engines and bicycles
How are bimetallic strips used in thermostats?
They emit heat based on temperature changes
They bend and complete or break an electrical circuit based on temperature changes.
They change color based on temperature changes
They expand and contract based on temperature changes
What are the advantages of using bimetallic strips in temperature control devices?
They provide precise temperature regulation
They cause temperature fluctuations
They are not durable
They are difficult to install
Discuss the benefits of using bimetallic strips in electrical devices.
They are used to reduce the temperature in electrical devices
They are used to increase the resistance in the circuit
Bimetallic strips are used to generate electricity
They have the ability to bend when heated, which can be used to control switches or circuit breakers.
What are the disadvantages of bimetallic strips in comparison to other temperature control methods?
Limited temperature range and high energy consumption
Higher cost and more complex design
Slower response time and less accuracy
Less durable and difficult to calibrate
Explain the limitations of bimetallic strips in industrial applications.
Bimetallic strips are highly durable and can withstand any industrial conditions.
Bimetallic strips have limited temperature range and may not be suitable for extreme industrial conditions.
Bimetallic strips have unlimited temperature range and are suitable for all industrial conditions.
Bimetallic strips are not affected by temperature changes in industrial applications.
How is a bimetallic strip constructed?
By bonding two different metals with different coefficients of thermal expansion together.
By weaving two metals together
By melting two metals and pouring them into a mold
By coating one metal with another metal
Describe the process of manufacturing a bimetallic strip.
Bonding two different metals with different coefficients of thermal expansion
Applying a layer of paint on a metal strip
Heating a metal strip to high temperatures
Using a single type of metal with uniform expansion rate
WHAT IS THE ROLE OF THE COMPRESSOR
COMPRESS LIQUID REFRIGERANT
CREATE PRESSURE DIFFERENCE
THE HEART OF THE REFRIGERATION CYCLE
METERS REFRIGERANT
WHAT IS THE ROLE OF THE CONDENSER
ABSORBS HEAT
METERS REFRIGERANT
CONDENSES GAS
REJECTS HEAT
what is refrigeration?
heating
drying
cooling
steaming
What is Pressure and state of the refrigerant in the suction pipe?
High pressure vapor
Low pressure vapor
Low pressure liquid
High pressure liquid
What is the function of the evaporator?
Reject heat.
Absorb Heat.
Create heat.
Mix refrigerant.
What is the function of the condenser in the cool mode?
Reject heat.
Absorb heat.
Mix the refrigerant.
Store refrigerant.
When leaving the compressor what state is the refrigerant in?
High Pressure, High Temperature gas
High Pressure, High Temperature liquid
Low Pressure, low Temperature gas
Low Pressure, low Temperature gas
One tonne of refrigeration is equal to
21 KJ/min
210 KJ/min
420 KJ/min
620 KJ/min
One tonne of refrigerating machine means that,
One tonne is the total mass of the machine
One tonne of refrigerant is used
One tonne of water can be converted into ice.
One tonne of ice when melts from and at 0oC in 24 hours, the refrigerating effect produced is equivalent to 210 KJ/min
One tonne of refrigerating machine means that,
One tonne is the total mass of the machine
One tonne of refrigerant is used
One tonne of water can be converted into ice.
One tonne of ice when melts from and at 0oC in 24 hours, the refrigerating effect produced is equivalent to 210 KJ/min
The co-efficient of performance is always.......one
Equal to
less than
Greater than
None of the above
The heat removing capacity of one tone of refrigeration is equal to?
210 Watt
210 kJ/hour
3.5 kJ/hour
3.5 W
Define refrigeration
It is the process of continuous cooling or extraction of heat to below that of the atmosphere from a substance with a help of the external work.
It is based on the second law of thermodynamics that the heat can made to flow from cold body to a hot body with the help of external source.
used to remove heat from the refrigerated space and reject it to atmosphere.
The function of evaporator is :
draw the refrigerant from the evaporator through suction valve at low pressure and to force it to the condenser through exhaust valve at high pressure and temperature.
to control the rate of admission of refrigerants to the evaporator.
to condense the refrigerants at saturation temperature from vapour to liquid by transferring its latent heat to the water.
Receive the liquid refrigerants from the condenser through throttle valve and to evaporate it
Heat exchanger is an equipment used to transfer heat from the hot fluid to cold fluid.
True
False
This figure represents what type of heat exchanger?
Double pipe
Plate and frame
Shell and tube
Compact
The color black
Reflects the wavelength of all colours
Should be used to keep cool
Absorbs the wavelength of all colours
Solar water heating system circulate a heat transfer fluid through a collector and a heat exchanger which heats the water is called ............................
Closed Loop System
Open Loop System
Short Loop System
In what form is solar energy is radiated from the sun?
Ultraviolet Radiation
Infrared Radiation
Electromagnetic Waves
What is the working principle of a solar water heating system?
A solar water heating system works by using nuclear energy to generate heat.
A solar water heating system works by using solar collectors to absorb sunlight and convert it into heat.
A solar water heating system works by using fossil fuels to generate heat.
A solar water heating system works by using wind turbines to generate heat.
How does a solar water heating system transfer heat to the water?
Convection
Solar collectors
Conduction
Radiation
Microwaves penetrate water and fat molecules and agitate them to create heat.
True
False
Microwaves work with...
Radio waves
Gama waves
X-rays
Ultra violet waves
