Question

Четыре лампы сопротивлением 4 Ом,5 Ом,10 Ом,20 Ом соеденены параллельно.Опеределите напряжение каждой лампе и силу тока в каждой из них,если в первой течет ток силой 2,5 А.Какова сила тока в неразветвленной части цепи?

Answer 1

Напряжение на всех лампах одинаковое U=I(1)*R(1)=2.5*4= !0 V
I(2)=U/R(2)=10/5=2 A; I(3)=U/R(3)=10/10=1 A;I(4)=U/R(4)=10/20=0.5 A
I=I(1)+I(2)+I(3)+I(4)=2.5+2+1+0.5=6 A

Answer 2

Calculation of Voltage and Current in Parallel Circuit

To determine the voltage and current in each lamp, we need to consider the total resistance of the circuit and the current flowing through it.

Given: - Four lamps with resistances of 4 Ω, 5 Ω, 10 Ω, and 20 Ω, respectively, connected in parallel. - The current flowing through the first lamp is 2.5 A.

To calculate the voltage across each lamp, we can use Ohm's Law, which states that V = I * R, where V is the voltage, I is the current, and R is the resistance.

Let's calculate the voltage across each lamp:

1. Lamp 1 (4 Ω): - Resistance (R1) = 4 Ω - Current (I1) = 2.5 A - Voltage (V1) = I1 * R1 = 2.5 A * 4 Ω = 10 V.

2. Lamp 2 (5 Ω): - Resistance (R2) = 5 Ω - Current (I2) = 2.5 A (since the lamps are connected in parallel, the current is the same for all lamps) - Voltage (V2) = I2 * R2 = 2.5 A * 5 Ω = 12.5 V.

3. Lamp 3 (10 Ω): - Resistance (R3) = 10 Ω - Current (I3) = 2.5 A - Voltage (V3) = I3 * R3 = 2.5 A * 10 Ω = 25 V.

4. Lamp 4 (20 Ω): - Resistance (R4) = 20 Ω - Current (I4) = 2.5 A - Voltage (V4) = I4 * R4 = 2.5 A * 20 Ω = 50 V.

Now, let's calculate the total current in the unbranched part of the circuit:

Since the lamps are connected in parallel, the total resistance (R_total) can be calculated using the formula:

1/R_total = 1/R1 + 1/R2 + 1/R3 + 1/R4.

Let's calculate the total resistance:

1/R_total = 1/4 Ω + 1/5 Ω + 1/10 Ω + 1/20 Ω.

Simplifying the equation:

1/R_total = (5/20 + 4/20 + 2/20 + 1/20) Ω = 12/20 Ω = 0.6 Ω.

R_total = 1/0.6 Ω = 1.67 Ω.

To calculate the total current (I_total) in the unbranched part of the circuit, we can use Ohm's Law:

I_total = V_total / R_total.

Since the voltage across each lamp is the same as the voltage across the unbranched part of the circuit, we can use any of the calculated voltages (V1, V2, V3, or V4) as V_total.

Let's use V1 as V_total:

I_total = V1 / R_total = 10 V / 1.67 Ω = 5.99 A.

Therefore, the current in the unbranched part of the circuit is approximately 5.99 A.

Please note that the calculated values are based on the given information and assumptions.