Question

an electric kettle takes 3A current at 220 V the time taken by the kettle to boil 0.5 kg of water from temprature at 50°C to 100°C
​

Answer 1

Given :

Current , I = 3 A

Voltage ,V = 220 V

Mass of water , m = 0.5 kg

Temperature change , Δt = 50°C

To find :

Time taken to boil the water from the temperature at 50°C to 100°C .

Solution :

let time be T .

s = 4200J / kg°C  {specific heat}

then ,

V * I * T = m * s * Δt

=> 220 * 3 * T = 0.5 * 4200 * 50

=> T = 105000 / 660

=> T = 159 sec approx.

Time taken to boil the water from the temperature at 50°C to 100°C is 159 seconds approx .