Calculate the time taken to heat 2kg of water from 50^\circC to 100^\circC in an electric kettle taking 5A, from a 210V supply. (Specific heat capacity of water = 4200\(kg^{-1}K{-1}\)
A
2.5 minutes
B
5.7 minutes
C
6.7 minutes
D
7.5 minutes
E
9.5 minutes
Verified Correct Answer: C.
Physical Principles & Numerical Solution
t = \(\frac{mc\theta}{p}\)
= \(\frac{2\times4200\times50}{210\times5}\) = 400s = 6.7minutes
Source: Myschool Past Questions Archive (Record #26284)