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