Question

Определите мощность, потребляемую первой лампой, если R1= 3 Ом, R2= 6 Ом, R3= 10 Ом, а вольтметр показывает 30 В r1 и r2 соединяются паралельно, а r12 и r3 последовательно,вольтметр измеряет только в самом конце r3

Answer 1

I=U/R3=30/10=3(V): R=R1*R2/R1+R2=2(Om): U1=I*R=3*2=6(V): I1=U1/R1=6/3=2(A): I2=U1/R2=6/6=1(A): Iобщ=I1+I2=2+1=3(A): P1=I1^2*R1= 2^2*3=12(Bt); P1=U1^2/R1=6^2/3=36/3=12(Bt)

Answer 2

Calculation of Power Consumed by the First Lamp

To determine the power consumed by the first lamp, we need to calculate the current flowing through it and then use Ohm's Law to find the power.

Given: - Resistance of R1 (r1) = 3 Ω - Resistance of R2 (r2) = 6 Ω - Resistance of R3 (r3) = 10 Ω - Voltmeter reading = 30 V

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

I = V / R

where I is the current, V is the voltage, and R is the resistance.

First, let's calculate the equivalent resistance of the parallel combination of r1 and r2:

1 / R_parallel = 1 / r1 + 1 / r2

1 / R_parallel = 1 / 3 + 1 / 6

1 / R_parallel = 2 / 6 + 1 / 6

1 / R_parallel = 3 / 6

1 / R_parallel = 1 / 2

R_parallel = 2 Ω

Now, let's calculate the total resistance of the circuit by adding r3 in series with R_parallel:

R_total = R_parallel + r3

R_total = 2 + 10

R_total = 12 Ω

Using Ohm's Law, we can find the current flowing through the circuit:

I = V / R_total

I = 30 / 12

I = 2.5 A

Now that we have the current, we can calculate the power consumed by the first lamp (r1) using the formula:

P = I^2 * r1

P = (2.5)^2 * 3

P = 6.25 * 3

P = 18.75 W

Therefore, the power consumed by the first lamp is 18.75 Watts.