As well as giving a cool look to photographs, polaroid filters are extremely useful for reducing glare in photos and snapping pictures of objects underwater

Which statement below describes a situation in which polarisation should happen?A.      Radio waves pass through a metal gridB.      Surface water waves are diffractedC.      Sound waves are reflectedD.      Ultrasound waves pass through a metal grid

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The resulting graph of the light intensity with angle, as the second polariser is rotated through 360°, looks as follows:

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As well as giving a cool look to photographs, polaroid filters are extremely useful for reducing glare in photos and snapping pictures of objects underwater

Broadcasting towers always transmit either vertically or horizontally polarised signals. This is why aerials must be positioned accordingly otherwise they won't pick up the TV signal correctly

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As the polarising filter B is rotated anticlockwise, the intensity of the light observed changes periodically depending on the angle B is rotated through When A and B have their transmission axes perpendicular to each other: Filter A will polarise the light in a certain axis This time none of the polarised light will pass through filter B In this case, the minimum intensity of light is transmitted

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Polarisation is when:Particle oscillations occur in only one of the directions perpendicular to the direction of wave propagation Polarisation can only occur in transverse waves This is because transverse waves oscillate in any plane perpendicular to the propagation direction

Broadcasting towers always transmit either vertically or horizontally polarised signals. This is why aerials must be positioned accordingly otherwise they won't pick up the TV signal correctly

As well as giving a cool look to photographs, polaroid filters are extremely useful for reducing glare in photos and snapping pictures of objects underwater

You may be expected to describe the intensity, or even draw the graph of intensity v angle, for light with two polarisers, however, the good news is that you won't be expected to perform any calculations (Malus's Law) in relation to this.

Diagram A shows: Only unpolarised waves can be polarised Diagram B shows: When a polarised wave passes through a filter with a transmission axis perpendicular to the wave, none of the wave will pass through Light can also be polarised through reflection, refraction and scattering

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As the polarising filter B is rotated anticlockwise, the intensity of the light observed changes periodically depending on the angle B is rotated through When A and B have their transmission axes perpendicular to each other: Filter A will polarise the light in a certain axis This time none of the polarised light will pass through filter B In this case, the minimum intensity of light is transmitted

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Broadcasting towers always transmit either vertically or horizontally polarised signals. This is why aerials must be positioned accordingly otherwise they won't pick up the TV signal correctly

When light is reflected from a reflective surface e.g. the surface of water or a wet road, it undergoes partial plane polarisation This means if the surface is horizontal, a proportion of the reflected light will oscillate more in the horizontal plane than the vertical plane Therefore, polaroid sunglasses are useful in reducing the glare on the surface of the water (or any reflective surface) as the partially-polarised light will be eliminated by the polarising filter As a result of this, objects under the surface of the water can be viewed more clearly When sunlight reflects off a horizontal reflective surface, such as water, the light becomes horizontally polarised. This is where polaroid sunglasses come in useful with their vertically aligned filter

Diagram A shows: Only unpolarised waves can be polarised Diagram B shows: When a polarised wave passes through a filter with a transmission axis perpendicular to the wave, none of the wave will pass through

Polaroid Sunglasses Polaroid sunglasses are glasses containing lens with polarising filters with transmission axes that are vertically oriented This means the glasses do not allow any horizontally polarised light to pass through

When sunlight reflects off a horizontal reflective surface, such as water, the light becomes horizontally polarised. This is where polaroid sunglasses come in useful with their vertically aligned filter

The resulting graph of the light intensity with angle, as the second polariser is rotated through 360°, looks as follows: Graph showing how the intensity of the transmitted beam varies with the angle between the transmission axes of the two polarisers

Polaroid Photography Polaroid cameras work in the same way as polaroid sunglasses They are very useful for capturing intensified colour and reducing glare on particularly bright sunny days

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Graph showing how the intensity of the transmitted beam varies with the angle between the transmission axes of the two polarisers

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Katie has always been passionate about the sciences, and completed a degree in Astrophysics at Sheffield University. She decided that she wanted to inspire other young people, so moved to Bristol to complete a PGCE in Secondary Science. She particularly loves creating fun and absorbing materials to help students achieve their exam potential.

When light is reflected from a reflective surface e.g. the surface of water or a wet road, it undergoes partial plane polarisation This means if the surface is horizontal, a proportion of the reflected light will oscillate more in the horizontal plane than the vertical plane Therefore, polaroid sunglasses are useful in reducing the glare on the surface of the water (or any reflective surface) as the partially-polarised light will be eliminated by the polarising filter As a result of this, objects under the surface of the water can be viewed more clearly

Polarisation of Radio & Microwave Signals Radio and television services are broadcast either horizontally-polarised or vertically-polarised Therefore, the reception aerial needs to be mounted flat (horizontal), or on its side (vertical), The particular orientation of an aerial will depend on the transmitter it is pointing towards and the polarity of the services being broadcast

Investigating Light Intensity with Two Polarisers If an unpolarised light source is placed in front of two identical polarising filters, A and B, with their transmission axes parallel: Filter A will polarise the light in a certain axis All of the polarised light will pass through filter B unaffected In this case, the maximum intensity of light is transmitted

Longitudinal waves (e.g. sound waves) cannot be polarised This is because they oscillate parallel to the direction of travel Waves can be polarised through a polariser or polarising filter This only allows oscillations in a certain plane to be transmitted

ANSWER: A Radio waves are transverse waves - they can be polarised by a metal grid so only the waves that fit through the grid will be transmitted, therefore, A is correct B cannot be correct as waves are not polarised when diffracted, but are polarised only when reflected, refracted or scattered C & D cannot be correct as polarisation only occurs for transverse waves, therefore, C & D can be ruled out as sound and ultrasound are both longitudinal waves

Longitudinal waves (e.g. sound waves) cannot be polarised This is because they oscillate parallel to the direction of travel Waves can be polarised through a polariser or polarising filter This only allows oscillations in a certain plane to be transmitted