X rays are formed by the use of short wave length electromagnetic waves. They have a high frequency.They are transmitted by passing through healthy tissue and then being absorbed by denser materials such as bones.
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What are CCD devices?
These alow images to be formed of the x ray electronically and they do this by silicon chips they detect x rays and produce signals to make high resolution images.
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What are 3 ways a radiographer can minimize exposure to X rays?
Wear lead aprons, Go behind a lead screen, Leave the room.
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What is ultrasound? What is the range of human hearing?
Ultrasound is sound at such a high frequency that we are unable to hear it. We hear around 20 - 20,000Hz.
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What happens when ultrasound waves hit a boundary?
When they hit a boundary they become partially reflected and they therefore send some of the ultrasound waves back. The time it takes for the sound to get back to the detector shows how far the boundary is away.
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S = V X T. What is this equation used to find out?
It is an osilloscope reading and used to find out time between boundaries.
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Name 2 ways ultrasound waves can be used.
By breaking down kidney stones. The use of prenatal scanning on the womb.
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What causes refraction?
Waves changing speed as they enter a different medium, due to the change in density.
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What will happen if a wave hits a boundary at 90 degrees?
It will not change direction but will slow down as it is going along the normal
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State what the refractive index is.
The refractive index is the ratio between the speed of light in a vacuum to the speed of light in that material.
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How to lenses form images?
By refracting light and changing its direction.
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What is a real image?
An image where light comes together to form an image on a screen.
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What is a virtual image
Where the light seems to be coming from somewhere else.
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What type of lenses do magnifying glasses use?
Converging lenses and it is always a virtual image.
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Complete the sentence... The more powerful the lens the more..
Strongly it converges and the shorter the focal length.
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What is the job of the cornea?
It does most of the eyes focusing. Due to having a high refractive index.
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What is the job of the iris?
It determines the color of the eye and changes the size of the pupil.
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What is the furthest point the eye can focus on?
Infinity
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What is the nearest point the eye can focus on?
25cm
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Other cards in this set
Card 2
Front
What are CCD devices?
Back
These alow images to be formed of the x ray electronically and they do this by silicon chips they detect x rays and produce signals to make high resolution images.
Card 3
Front
What are 3 ways a radiographer can minimize exposure to X rays?
Back
Card 4
Front
What is ultrasound? What is the range of human hearing?
Back
Card 5
Front
What happens when ultrasound waves hit a boundary?
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