The circuit below is used to heat water kept in a bucket. Assuming heat loss only by Newton's law of cooling, the variation in the temperature of the water in the bucket as a function of time is depicted by

Step-by-step solution

In given condition, Heat gained by water heater - Heat lost governed by Newton's law of cooling = Net heat gained by water ⇒ i 2 R 1 - K T - T 0 = m S Δ T Δ t Here, T = temperature and t = time. ⇒ d T d t = i 2 R 1 m S - K m S T - T 0 = i 2 R 1 m S + K T 0 m S - K m S T Above equation can be written as, d T d t = A + B T or d T A + B T = d t Integrating, we get ⇒ 1 B . log e A + B T = t ⇒ A + B T = e t B ⇒ T = 1 B e t B - A Hence, temperature T depends on time t exponentially. ∴ Best suitable graph is