Question 1
Question
Ultrasound waves are partially ________ when they meet a boundary between two different media.
Question 2
Question
Ultrasound wave facts:
Answer
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Can be produced by electronic systems
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Have a frequency lower than 20000Hz
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Have a frequency higher than 20000Hz
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An electromagnetic wave beyond the red end of the visible spectrum
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An electromagnetic wave beyond the blue end of the visible spectrum
Question 3
Question
X-rays have a very short wave length and cause ionisation
Question 4
Question
X-rays can't be used to diagnose and treat medical conditions
Question 5
Question
Properties of X-rays:
Answer
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absorbed by metal and bone
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transmitted by soft tissue
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reflected by soft tissue
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doesn't effect photographic film in the same way as light
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effects photographic film in the same way as light
Question 6
Question
What is refraction?
Question 7
Question
A lens forms an image by refracting light
Question 8
Question
how is the nature of an image defined:
Question 9
Question
Which lens is used in a magnifying glass?
Question 10
Question
Visible light can be sent along optical fibres
Question 11
Question
What is long sight caused by?
Answer
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Eyeball being too short
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Eyeball being to long
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The lens is too weak
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The lens is too strong
Question 12
Question
Where can the eye focus on objects?
Answer
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Between the principal focus and the far point
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Between the near point and the far point
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Between the near point and the principal focus
Question 13
Question
The power of a lens is given by P=1/f
Question 14
Question
The greater the refractive index
Answer
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The flatter the lens
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The thicker the lens
Question 15
Question
What does a camera lens and the eye have in common?
Answer
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The CCDs in a digital camera is the equivalent of the retina
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They are both diverging lens'
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They are both converging lens'
Question 16
Question
Focal length is determined by:
Question 17
Question
Power is measured in Dioptres, D
Question 18
Question
The time period depends on the force being applied
Question 19
Question
The centre of mass of a symmetrical object is:
Question 20
Question
The centre of mass is that point where the mass of an object is thought to be
Answer
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Centered
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Concentrated
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Clear
Question 21
Question
What is the turning effect of a force called?
Question 22
Question
If the line of action of weight of an object lies inside the base of the object there will be a resultant moment and it will topple.
Question 23
Question
What is the moment of a force measured in?
Answer
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D (dioptres)
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m/s (metres per second)
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Nm (Newton-metres)
Question 24
Question
the centripetal force need to make an object perform circular motion increases as:
Answer
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Mass decreases
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Mass increases
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Radius decreases
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Radius increases
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Speed decreases
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Speed increases
Question 25
Question
The acceleration towards the centre of a circle changes the direction of the body and its speed.
Question 26
Question
What is the resultant force causing acceleration called?
Answer
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Centripecal force
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Centripical force
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Centripetal force
Question 27
Question
Liquids are compressible
Question 28
Question
Pressure in liquids is transmitted equally in all directions
Question 29
Question
Using different cross sectional areas of a hydraulic system means it can be used as a force multiplier.
Question 30
Question
what is produced around a wire when current flows though it?
Question 31
Question
The size of a force can be increased by:
Answer
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Increasing the size of the wire
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Increasing the size of the current
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Increasing the size of the voltage
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Increasing the strength of the magnetic field
Question 32
Question
When will the conductor not experience a force?
Question 33
Question
In flemings left hand rule:
Answer
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the first finger is the magnetic field direction
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The second finger is the strength of the current
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The second finger is the direction of the current
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The thumb is the direction of the current
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The thumb is the motion of the wire
Question 34
Question
Switch mode transformers use a lot of power when are switched on but no load is applied.
Question 35
Question
Switch mode transformers are much lighter and smaller than normal transformers working from a 50Hz mains supply
Question 36
Question
What does it mean if the electrical power input is equal to the electrical power output in a transformer?
Answer
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It is 100% efficient
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Heat energy was lost
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Its 0% efficient
Question 37
Question
In a step down transformer:
Answer
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The potential difference across the secondary coil is more than the potential difference across the primary coil
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The potential difference across the secondary coil is less than the potential difference across the primary coil
Question 38
Question
In a step up transformer:
Answer
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The potential difference across the secondary coil is less than the potential difference across the primary coil
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The potential difference across the secondary coil is more than the potential difference across the primary coil
Question 39
Question
What does an alternating current in the primary coil produce?
Question 40
Question
What does a changing magnetic field induce in a transformer?
Question 41
Question
If a magnet is moved into a coil or wire of potential difference is induced across the ends of the coil
Question 42
Question
If an electrical conductor cuts through a magnetic field a potential difference is induced across the ends of the conductor
Question 43
Question
Which of these options are part of the basic structure of a transformer?
Answer
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Two coils around a soft core
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One coil around a soft core
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De magnetising soft iron
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Magnetising soft iron
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Layers of iron (Laminated)
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One layer (meaning laminated)