A 50W electric heater is used to heat a metal block of mass 5kg. If in 10 minutes a temperature rise of 12oC is achieved, the specific heat capacity of the metal is
A
400 J kg-1K-1
B
500 J kg-1K-1
C
390 J kg-1K-1
D
130 J kg-1K-1
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Heat supplied by the heater in 10 mins
= power x time
= 50 x (10 x 60)
= 30000 J
This heat is equal = MCΔt
= 5 x c x 12
= 60cJ
= 60C = 30,000
C = 30,000/60
C = 500 J kg-1K-1
Source: Myschool Past Questions Archive (Record #12941)