Polarized sunglasses use polarizing filters to block horizontally polarized glare reflected from surfaces (water, roads). LCD displays use liquid crystals to rotate polarization, controlling light transmission through polarizers. Memory tip: 'Polarization applications: glare reduction (sunglasses), display technology (LCDs), 3D movies'. This application question tests wave optics uses, frequently appearing in competitive exams. Always link physical principles to everyday technologies; competitive exams emphasize practical relevance of physics concepts, making abstract phenomena tangible through common devices.
Explanation:
Distance ≈ 1.5×10¹¹ m, c = 3×10⁸ m/s ⇒ t = 500 s ≈ 8.3 min. Standard astronomical fact. Memory aid: 'Sunlight takes 8 minutes; we see Sun as it was 8 min ago'. Scale knowledge frequently tested in competitive exams.
Explanation:
Fuse is a safety device with a wire that melts when current exceeds rated value, breaking the circuit and preventing damage from overcurrent/short circuits. It operates on Joule heating (I²R). Option A is opposite; C describes capacitor; D describes rectifier. Memory tip: 'Fuse = sacrificial overcurrent protector'. This practical application question tests knowledge of electrical safety devices, frequently examined in competitive exams. Always link fuse rating to circuit requirements: fuse current rating slightly above normal operating current.
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