The ratio of SI to CGS unit of force is MCQ with Answer and Explanation

Explanation:
Phase difference 90°, power factor zero, average power zero.

Explanation:
Steel has high retentivity, retains magnetism, used for permanent magnets. Soft iron has low retentivity, used for electromagnet core (temporary). Alnico, ferrites also used.

Explanation:
KE ∝ p² (since KE = p²/(2m)). If KE increases by 300%, new KE = 4× original KE. Thus p_new² / p_original² = 4 ⇒ p_new / p_original = 2 ⇒ momentum doubles, i.e., 100% increase. Memory tip: 'KE ∝ p²; so %Δp = ½ %ΔKE for small changes, but for large changes use ratio'. This proportional reasoning problem tests energy-momentum relationship, frequently appearing in competitive exams. Always derive from fundamental relations when percentages are large; linear approximations fail here.