Question

Електрична праска потужністю 800 Вт працює від джерела постійної напруги 220 В. Визначити силу струму в нагрівному елементі праски та її опір в робочому стані. Скільки енергії виділиться за 1,5 години безперервної роботи праски?

Answer 1

Ответ:

Объяснение:

Дано:

P=800 Вт

U=220 B

t=1,5 часа = 1,5*3600=5400 с

найти:

I

R

Q

Решение

P=UI, откуда

I=P/U

I=800/220=3,6 A

P=(U²)/R

R=(U²)/P = 60,5 Ом

Q=U*I*t = 220*3,6*5400= 4276800 Дж ≈ 4,3 MДж

Answer 2

Calculation of Current and Resistance:

To determine the current flowing through the heating element of the iron and its resistance in the working state, we can use Ohm's Law. Ohm's Law states that the current flowing through a conductor is equal to the voltage across the conductor divided by its resistance.

Given: - Power of the iron: 800 W - Voltage of the power source: 220 V

To find the current flowing through the heating element, we can use the formula:

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

Substituting the given values:

Current (I) = 800 W / 220 V

Calculating the current:

Current (I) = 3.64 A

Therefore, the current flowing through the heating element of the iron is approximately 3.64 Amperes.

To find the resistance of the heating element, we can rearrange Ohm's Law:

Resistance (R) = Voltage (V) / Current (I)

Substituting the given values:

Resistance (R) = 220 V / 3.64 A

Calculating the resistance:

Resistance (R) = 60.44 Ω

Therefore, the resistance of the heating element in the working state is approximately 60.44 Ohms.

Calculation of Energy Released:

To calculate the energy released by the iron during 1.5 hours of continuous operation, we can use the formula:

Energy (E) = Power (P) * Time (t)

Given: - Power of the iron: 800 W - Time of continuous operation: 1.5 hours

Substituting the given values:

Energy (E) = 800 W * 1.5 hours

Converting hours to seconds (1 hour = 3600 seconds):

Energy (E) = 800 W * 1.5 * 3600 seconds

Calculating the energy:

Energy (E) = 4,320,000 Joules

Therefore, the iron will release approximately 4,320,000 Joules of energy during 1.5 hours of continuous operation.

Please note that the above calculations are based on the given information and assumptions.