The prefix 'pico' represents MCQ with Answer and Explanation

Explanation:
1 cal = 4.186 J ≈ 4.2 J. So both are correct. However option D covers both. I'll set D as correct.

Explanation:
For resistors in parallel, the reciprocal of the equivalent resistance (1/Rp) is the sum of the reciprocals of individual resistances. 1/Rp = 1/R1 + 1/R2 + 1/R3 = 1/2 + 1/3 + 1/6. Finding a common denominator (6): 1/Rp = 3/6 + 2/6 + 1/6 = 6/6 = 1. Therefore, Rp = 1 Ω.

Explanation:
T ∝ 1/√g. If g' = 4g, T' = T/√4 = T/2. Higher gravity ⇒ faster oscillations. Memory aid: 'Pendulum: T ∝ 1/√g; 4× gravity ⇒ half period'. Oscillations proportionality frequently tested in competitive exams.