The specific resistance (resistivity) of a metallic conductor depends exclusively upon its: MCQ with Answer and Explanation

Explanation:
Step-up transformer increases voltage and decreases current proportionally (P = V×I constant ideal). Power constant (ignoring losses). Used in power transmission to reduce I²R losses. Step-down decreases voltage.

Explanation:
The beat frequency is |fA - fB|. So fA is either 256+5=261 Hz or 256-5=251 Hz. Adding wax increases mass, which strictly decreases frequency. If fA was 261, decreasing it brings it closer to 256, reducing beats to 2 (e.g., 258-256=2). If it was 251, decreasing it would increase the beats (e.g., |248-256|=8). Thus, it was 261 Hz.

Explanation:
Pendulum period T = 2π√(l/g) for small amplitudes. It depends on length l and gravity g, but not on bob mass or amplitude (isochronism for small angles). Mass independence arises because gravitational force and inertia both proportional to mass, canceling out. Memory aid: 'Pendulum: T ∝ √(l/g); independent of mass and small-amplitude'. This conceptual question tests oscillations fundamentals, frequently examined in competitive exams. Always verify the small-angle approximation; competitive exams assume it unless specified otherwise. This problem assesses understanding of which parameters affect periodic motion.