A pendulum has time period 2 s. If its length is increased by 4 times, new period is MCQ with Answer and Explanation

Explanation:
The transformer equation relates voltages to the number of turns: V_secondary / V_primary = N_secondary / N_primary. We have N_p = 50, N_s = 1000, and V_p = 220V. Substituting the values gives V_s / 220 = 1000 / 50. V_s = 220 * 20 = 4400 Volts. This is a step-up transformer, increasing the voltage strictly by a factor of 20.

Explanation:
T=2π√(L/g) => L = gT²/(4π²) ≈ (9.8×4)/(4×9.87) ≈ 1 m.

Explanation:
Conservative forces (gravity, spring, electrostatic) have path-independent work; work done over any closed loop is zero. This defines conservative forces and enables potential energy definition. Non-conservative forces (friction) have non-zero closed-path work. Memory aid: 'Conservative force: ∮F·dr = 0; enables energy conservation'. This mechanics concept is frequently tested in competitive exams. Always link conservative forces to potential energy and mechanical energy conservation; this is foundational for advanced physics problem-solving.