Question

a series circuit contains two devices, one with a resistance of 10 ohms and one with a resistance of 4 ohms. if the generator supplies a voltage of 42 v, whats the magnitude of the current?

a) 1.75 a
b) 3 a
c) 1.33 a
d) 2 a

Explanation:

Identify given values

We are given a series circuit with two resistors:

• First resistance \(R_1 = 10\ \Omega\)
• Second resistance \(R_2 = 4\ \Omega\)
• Total voltage supplied \(V = 42\text{ V}\)

Calculate equivalent resistance

For a series circuit, the total equivalent resistance \(R_{\text{eq}}\) is the sum of the individual resistances:

$$ R_{\text{eq}} = R_1 + R_2 $$

$$ R_{\text{eq}} = 10\ \Omega + 4\ \Omega = 14\ \Omega $$

Calculate total current

Using Ohm's law, we find the current \(I\) flowing through the circuit:

$$ I = \frac{V}{R_{\text{eq}}} $$

$$ I = \frac{42\text{ V}}{14\ \Omega} = 3\text{ A} $$

Answer:

• (A) 1.75 A
• (B) 3 A (Correct answer)
• (C) 1.33 A
• (D) 2 A