We (MS Classes) have tried explaining the answers of the 2018 CBSE Physics Board Paper through this video. Here, we have mainly explained the conceptual question & numerical in detail so that 2018 (onward) aspirants can take the benefit of it. Here, I am explaining some of the answers of the board questions in brief:
a) Q3 b) — UV radiation (along with IR) can also be preferable for Eye Surgery (as referred from some text books)
b) Q17 b)— There is no total internal reflection as the angle of incidence (at AC) which is 60 degree, is coming less than critical angle (which is around 62 degree)
c) Q20 b) — Torque on the magnet in the final orientation is 0 as angle b/w Magnetic Moment & Magnetic Field is 180 degree.
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