The sky appears blue due to MCQ with Answer and Explanation

Explanation:
To convert a temperature from Celsius to Kelvin, the formula is K = °C + 273.15. For most physics problems, we use 273. Therefore, K = 25 + 273 = 298 K. Kelvin is the SI unit of temperature, and it never uses a degree symbol.

Explanation:
v² = 2gh = 2×10×20=400, v=20 m/s.

Explanation:
R ∝ L/A. New L'=2L, A'=A/2 => R' = ρ(2L)/(A/2) = 4ρL/A = 4R. Alternatively, volume constant? Not given, here both changed independently. So 4R.