Question

Use the DC Construction kit to build a simple circuit to perform the following task:

You are asked to use a single resistor and a 110 V DC battery for the purpose of boiling a litter of water (4,184 Joule/Kg*degree Celsius), with a starting temperature of 20 C, in exactly 4 minutes.

Answer 1

The resistance is 8.7 ohm.

Step-by-step explanation:

Voltage, V = 110 V

mass, m = 1 kg

change in temperature, T = 100 - 20 = 80 C

time, t = 4 min = 4 x 60 = 240 s

specific heat, c = 4184 J/kg C

let the resistance is R.

The heat generated by the heater is used to the heat the water.

`(V^2)/(R) t = m c T \\\\(110^2)/(R)* 240 = 1* 4184* 80\\\\R = 8.7 ohm`