Question

В электрокипятильнике ёмкость 5л с КПД 70% вода нагревается от 10градусов цельсия до 100 градусов цельсия за 20 мин.Какой силы ток проходит по обмотке нагревателя если напряжение в сети 220 В

Answer 1

Количество теплоты выделяемое на нагрев воды равно
Q1=cmΔT=4200*5*90=1890кДж
Количество теплоты выделяемое кипятильником
Q2=U*I*t=?
КПД=Q1/Q2=1890кДж/Q2
Q2=Q1/КПД
UIt=Q1/КПД
I=Q1/(U*t*КПД)=$\frac{1890000}{0.7*1200*220} =10.2$А

Answer 2

Calculating Current Passing Through the Heating Element

To calculate the current passing through the heating element of the electric kettle, we can use the formula:

Power (P) = Voltage (V) × Current (I)

We can rearrange this formula to solve for the current (I):

Current (I) = Power (P) / Voltage (V)

First, let's calculate the power (P) used by the heating element.

The energy required to heat the water can be calculated using the formula:

Energy = Mass × Specific Heat Capacity × Temperature Change

Given: - Mass of water (m) = 5 kg (since 1 liter of water is approximately 1 kg) - Specific heat capacity of water (c) = 4.18 kJ/kg°C - Temperature change (ΔT) = 100°C - 10°C = 90°C

Using the formula, the energy required to heat the water is:

Energy = 5 kg × 4.18 kJ/kg°C × 90°C

Let's calculate the energy required.

Now, we can calculate the power (P) used by the heating element using the time taken for heating.

Power (P) = Energy / Time

Given: - Time taken (t) = 20 minutes = 20/60 hours

Let's calculate the power (P) used by the heating element.

Finally, we can use the power (P) and the given voltage (V) to calculate the current (I) passing through the heating element.

Current (I) = Power (P) / Voltage (V)

Let's calculate the current passing through the heating element.