8 (a) Which colour of visible light has the longest wavelength?
A blue
B green
C red
D yellow
(b) Some television remote controls use infrared radiation and other remote controls use radio waves - Edexcel - GCSE Physics - Question 8 - 2019 - Paper 1
Question 8
8 (a) Which colour of visible light has the longest wavelength?
A blue
B green
C red
D yellow
(b) Some television remote controls use infrared radiati... show full transcript
Worked Solution & Example Answer:8 (a) Which colour of visible light has the longest wavelength?
A blue
B green
C red
D yellow
(b) Some television remote controls use infrared radiation and other remote controls use radio waves - Edexcel - GCSE Physics - Question 8 - 2019 - Paper 1
Step 1
Which colour of visible light has the longest wavelength?
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Answer
The color of visible light that has the longest wavelength is C red.
This is because the wavelength of red light is approximately 620 to 750 nanometers, which is longer than the wavelengths of blue, green, and yellow light.
Step 2
Explain why an infrared remote control may not switch on the television from behind an armchair but a radio wave remote control always will.
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Answer
Infrared remote controls rely on line-of-sight transmission, meaning that if the infrared signal is blocked by an object, such as an armchair, it cannot reach the television. This limits the functionality of infrared remotes, as any obstruction can prevent them from operating.
On the other hand, radio wave remote controls utilize longer wavelengths that can penetrate walls and other barriers, allowing them to function effectively even when there is an obstruction between the remote and the television.