A body weighs 100 N on Earth's surface. Weight at a height equal to Earth's radius is MCQ with Answer and Explanation

Explanation:
For closed pipe, fundamental f = v/(4L) = 340/(4×0.16) = 340/0.64 ≈ 531 Hz, close to 512 Hz, slight difference due to end correction. So fundamental. Approx match, SSC type.

Explanation:
Femto (f) = 10⁻¹⁵. Pico (p) = 10⁻¹², nano (n) = 10⁻⁹, atto (a) = 10⁻¹⁸. The prefix chain: milli 10⁻³, micro 10⁻⁶, nano 10⁻⁹, pico 10⁻¹², femto 10⁻¹⁵, atto 10⁻¹⁸. Mnemonic: Femto is 'fifteen'.

Explanation:
Gamma rays (photons) have highest penetration, stopped by thick lead/concrete. Alpha least (paper/skin). Beta intermediate (aluminium). Neutrons also penetrating but not listed. Gamma has no charge.