Correct Answer - Option 3 : 2440 kJ/kg
Concept:
The total heat supplied will be comprised of heat supplied up to saturated water state and then latent heat.
Total heat will be Q = CP ΔT + x hfg
Calculation:
Given CP = 4 kJ/kg K; ΔT = 100 - 30 = 70°C, x = 0.9, hfg = 2400 kJ/kg
Q = 4 × 70 + 0.9 × 2400 = 2440 kJ/kg