Question

В сеть с напряжением 120 В включено параллельно 50 ламп с сопротивлением 240,0 Ом каждая. Определить общую силу тока в лампах и падение напряжения на магистрали, если проводка от магистрали до потребителя имеет сопротивление 0,280 Ом.

Answer 1

Пусть n=50 Общее сопротивление R=R1/n=240/50=4,8 Ом
Общая сила тока в цепи I=U/R=120/4,8=25 A
Ток в каждой лампе I1=I/n=25/50=0,5 А
Падение напряжения в проводах Up=I*Rp=25*0,28= 7В

Answer 2

Calculation of Total Current and Voltage Drop

To determine the total current in the lamps and the voltage drop across the main line, we can use Ohm's Law and the principles of parallel circuits.

Given information: - Voltage in the network: 120 V - Number of lamps connected in parallel: 50 - Resistance of each lamp: 240.0 Ω - Resistance of the main line: 0.280 Ω

Step 1: Calculate the total resistance of the parallel circuit.

In a parallel circuit, the total resistance (R_total) is given by the reciprocal of the sum of the reciprocals of the individual resistances.

R_total = 1 / (1/R1 + 1/R2 + 1/R3 + ... + 1/Rn)

In this case, since all the lamps have the same resistance, we can simplify the equation:

R_total = 1 / (1/240 + 1/240 + 1/240 + ... + 1/240)
        = 1 / (50/240)
        = 240/50
        = 4.8 Ω

Step 2: Calculate the total current flowing through the parallel circuit.

Using Ohm's Law, we can calculate the total current (I_total) flowing through the parallel circuit:

I_total = V / R_total
        = 120 / 4.8
        = 25 A

Therefore, the total current flowing through the lamps is 25 A.

Step 3: Calculate the voltage drop across the main line.

To calculate the voltage drop across the main line, we can use Ohm's Law:

V_drop = I_total * R_line
       = 25 * 0.280
       = 7 V

Therefore, the voltage drop across the main line is 7 V.

Conclusion

In summary, the total current flowing through the lamps is 25 A, and the voltage drop across the main line is 7 V.