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
Correct Answer: Option B
Explanation
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