Question

Two Physics quick help

Answer 1

Answer:

21.3 V, 1.2 A

Explanation:

1.

These resistors are in series, so the net resistance is:

R = R₁ + R₂ + R₃

R = 20 + 30 + 45

R = 95

So the current is:

V = IR

45 = I (95)

I = 9/19

So the voltage drop across R₃ is:

V = IR

V = (9/19) (45)

V ≈ 21.3 V

2.

First, we need to find the equivalent resistance of R₂ and R₃, which are in parallel:

1/R₂₃ = 1/R₂ + 1/R₃

1/R₂₃ = 1/10 + 1/10

R₂₃ = 5

Now we find the overall resistance by adding the resistors in series:

R = R₁ + R₂₃ + R₄

R = 10 + 5 + 10

R = 25

So the current through R₁ is:

V = IR

30 = I (25)

I = 1.2 A