Half-life 5 days. Fraction remaining after 15 days: MCQ with Answer and Explanation

Explanation:
Boiling occurs when vapour pressure equals atmospheric pressure. At high altitude, atmospheric pressure is lower, so water boils at lower temperature. Pressure cooker increases pressure to raise boiling point for faster cooking.

Explanation:
V_s/V_p = N_s/N_p ⇒ V_s = 100×(5/1) = 500V. Step-up transformer increases voltage. Memory aid: 'Turns ratio = voltage ratio; current ratio inverse'. Direct transformer formula application frequently tested in competitive exams with ratio calculations.

Explanation:
F = G m1 m2 / r² => G = F r² / (m1 m2) => [MLT⁻²][L²]/[M²] = [M⁻¹L³T⁻²].