How long will it take to heat 4 kg of water from 30ºC to 65ºC using an electric kettle taking 5 A from a 240 V supply?
(Specific heat capacity of water = 4200 J kg\(^{-1}\) K\(^{-1}\))
A
160 s
B
245 s
C
490 s
D
150 s
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Answer: C
Time = \(\frac{(mcΔT)}{(VI)}\) = \(\frac{588000}{1200}\) = 490 s.
Source: WAEC / JAMB / NECO Classroom Archive (Record #74376)