Correct Answer - Option 3 : 103
Concept:
Heat absorbed by aluminum block:
δQ = mcΔT
Calculation:
Given:
Power of the machine, P = 10 kW
Now,
As 50% of power is used in heating
∴ Heat generated = 0.5 P = 5 kW = 5 kJ/s
Heat generated in 2.5 min (i.e 150 s),
∴δQ = 5 × 150 = 750 kJ
Heat absorbed by aluminum block:
δQ = mcΔT
750 = 8 × 0.91 × ΔT
ΔT = 103°C