EIT Electrical Circuits 2

Question 1

In an AC circuit, inductive reactance X_L is calculated as:

Accepted Answer

2πfL

Answer

Inductive reactance X_L = 2πfL = ωL, where f is frequency and L is inductance in henries.

Question 2

What theorem states that any linear two-terminal circuit can be replaced by a single voltage source and series resistance?

Accepted Answer

Thevenin's Theorem

Answer

Thevenin's Theorem simplifies complex networks to a voltage source V_th in series with resistance R_th.

Question 3

At resonance in a series RLC circuit, the impedance is:

Accepted Answer

Minimum (equal to R)

Answer

At resonance, inductive and capacitive reactances cancel (X_L = X_C), leaving only resistance, so Z is minimum and equal to R.

Question 4

What is the phase relationship between voltage and current in a pure inductor?

Accepted Answer

Voltage leads current by 90°

Answer

In a pure inductor, voltage leads current by 90° (π/2 radians) because V = L(dI/dt).

Question 5

The turns ratio of a transformer is 10:1 (primary:secondary). If the primary voltage is 120V, what is the secondary voltage?

Accepted Answer

12 V

Answer

V_s/V_p = N_s/N_p → V_s = 120 × (1/10) = 12 V.

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