An electric kettle, connected to a 240V mains, produces 6.0 x 105J of heat energy to boil a quantity of water in 5 minutes. Find the resistance of the kettle.
A
14.4\(\Omega\)
B
28.8\(\Omega\)
C
144\(\Omega\)
D
288\(\Omega\)
E
2880\(\Omega\)
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Heat energy = Electrical energy
6 x 105 = \(\frac{V^2}{R}\)t
R = \(\frac{240 \times 240 \times 5 \times 60}{6 \times 105}\)
= 28.8\(\Omega\)
Source: Myschool Past Questions Archive (Record #28649)