The boiling point of water on Kelvin scale is MCQ with Answer and Explanation

Explanation:
Apparent weight = m(g+a) = 60×(10+2) = 720 N, which corresponds to 72 kg mass on scale (if scale calibrated in kg under g=10). Reading 72 kg. Downward acceleration would reduce.

Explanation:
LEDs are highly efficient, converting ~80-90% of electrical energy into light, rest heat. Incandescent bulbs ~10% efficient. LED long life, low power. Blue LED Nobel prize 2014.

Explanation:
Plane mirror forms virtual, erect, same size, laterally inverted image behind mirror. Used in periscope, looking glass. Distance behind mirror equals object distance.