Sarthaks APP
+1 vote
in Physics by (59.8k points)

An immersion heater rated 1000W, 220V is used to heat 0.01m3 of water. Assuming that the power is supplied at 220V and 60% of the power supplied is used to heat the water, how long will it take to increase the temperature of the water from 15°C to 40° C?

1 Answer

+1 vote
by (147k points)
selected by
Best answer

P = 1000

V = 220v

R = V2/P = 48400/1000 = 48.4Ω

Mass of water = 1/100 x 1000 = 10kg

Heat required to raise the temp. of given amount of water = msΔt = 10 × 4200 × 25 = 1050000

Now heat liberated is only 60%. So V2/R x T x 60% = 1050000

=> (220)2/48.4 x 60/100 x T = 1050000 => T = 10500/6 x 1/60nub = 29.16min

Sarthaks APP

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.