Question

Напряжение на клеммах прибора 5В, мощность тока равна 4Вт. Определите: а) сопротивление прибора;б) работу, которую совершает электрический ток за 4 минСрочно, помогите пожалуйста!!

Answer 1

Объяснение:

А) Мощность тока рассчитывается по формуле :

P = U * I

По закону Ома для участка цепи:

I = U / R

Подставляем в первую формулу:

P = U * U/R = U² / R

Выражаем сопротивление :

R = U² / P

R = ( 5 В) ² / 4 Вт = 25 В / 4 Вт = 6,25 Ом

б) Работа электрического тока рассчитывается по формуле :

A = U * I * t

A = U * U/R * t = U²/R * t

A = (5 В)² / 6,25 Ом * 240с = 960 Дж

Ответ: а) 6,25 Ом

б) 960 Дж

Answer 2

Calculation of Resistance:

To determine the resistance of the device, we can use Ohm's Law, which states that the voltage across a resistor is equal to the current flowing through it multiplied by its resistance. The formula for Ohm's Law is:

V = I * R

Given that the voltage across the device is 5V and the power of the current is 4W, we can use the formula for power:

P = V * I

We can rearrange this equation to solve for current:

I = P / V

Substituting the given values:

I = 4W / 5V = 0.8A

Now, we can substitute the values of voltage and current into Ohm's Law to calculate the resistance:

R = V / I = 5V / 0.8A = 6.25Ω

Therefore, the resistance of the device is 6.25Ω. [[1]]

Calculation of Work Done by Electric Current:

To calculate the work done by the electric current, we can use the formula:

Work = Power * Time

Given that the power of the current is 4W and the time is 4 minutes, we need to convert the time to seconds:

Time = 4 minutes * 60 seconds/minute = 240 seconds

Substituting the values into the formula:

Work = 4W * 240s = 960 Joules

Therefore, the work done by the electric current over 4 minutes is 960 Joules. [[2]]

I hope this helps! Let me know if you have any further questions.