A lamp is switched on and viewed through two polarising filters P and Q, as shown - Edexcel - A-Level Physics - Question 5 - 2023 - Paper 2
Question 5
A lamp is switched on and viewed through two polarising filters P and Q, as shown.
The lamp appears dark when viewed through P and Q. Q is rotated through 180°.
Wh... show full transcript
Worked Solution & Example Answer:A lamp is switched on and viewed through two polarising filters P and Q, as shown - Edexcel - A-Level Physics - Question 5 - 2023 - Paper 2
Step 1
Angle of rotation of 90°
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Answer
When filter Q is rotated by 90°, it will allow light that has been polarized by filter P to pass through. Therefore, the lamp will appear bright.
Step 2
Angle of rotation of 180°
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Answer
After the 180° rotation, filter Q will be perpendicular to filter P, meaning it will block the light that has been polarized by filter P. Thus, the lamp will again appear dark.
