-Electromagnetic waves Flashcards
What is amplitude?
The maximum displacement of a point on a wave from its position when it’s undisturbed (at equilibrium).
What are electromagnetic waves?
Transverse waves that form a continuous spectrum, all of which travel at the same speed, that transfer energy from a source to an absorber.
What defines a transverse wave?
A wave that doesn’t require a medium to travel through and therefore can travel through a vacuum.
Depending on what the substance is, what can electromagnetic waves do?
They can either refract, reflect, absorb or transmit waves.
When a wave refracts through a glass cube what does it normally do in correlation to the angles of incidence and refraction?
The angle of incidence is greater than the angle of refraction due to the velocity decrease of the wave causing it to bend towards the normal.
What are the uses of radio waves and what are their dangers?
They can be used in radios and to connect two devices together without any devices like bluetooth as well as TV communications.
They can be dangerous as they can penetrate through skin and heat internal body parts.
What are the uses of micro waves and what are their dangers?
They can be used for heating food and can also be used in satellites and mobile networks.
They can be absorbed by the water molecules inside of us and they can therefore heat up internal body parts.
What are the uses of infrared waves and what are their dangers?
They can be used to heat food up and to detect heat which may be used in security alarms and criminology jobs.
They can be dangerous as high intensity sources can lead to skin burns.
What are the uses of visible light and what are their dangers?
They enable us to see, take pictures using a camera, LASERS.
They can cause eye damage and blindness.
What are the uses of UV waves and what are their dangers?
They can help detect bodily fluids, forged money. Used in tanning beds.
They can cause skin damage.
What are the uses of X rays and what are their dangers?
They can be used in medical imaging, producing X-rays and CT scans. At higher doses they can be used to treat cancer. Industrial imaging and to detect weapons at airports.
Very ionising and can easily penetrate and damage living cells and tissues which may develop into cancer.
What are the uses of Gamma waves and what are their dangers?
Sterilisation, food preservation, medical imaging and therapy, astronomy.
Very ionising and can easily penetrate and damage living cells and tissues which may develop into cancer.
What is the equation linking wave speed, wavelength and frequency?
Wave speed= Wavelength x frequency
Wave speed= m/s
Frequency= hz
Wavelength= m
What is the equation for speed?
Speed= distance / time
What can X rays be absorbed by?
Elements with higher atomic numbers (that have more electrons) because the X-rays collide with the electrons, making them be absorbed easily. So in X-rays imaging, this is shown by a white background
