Photoelectric emission requires: MCQ with Answer and Explanation

Explanation:
Pole strength is a property of the magnet; when cut transversely, each piece still has both north and south poles with same pole strength as original. Magnetic moment becomes half because length halves. Each is a complete magnet.

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.

Explanation:
Refrigerant evaporates inside absorbing heat, compressed outside releasing heat, cycle repeats.