EETC Circuit Theory 4

Question 1

Norton's equivalent circuit consists of:

Accepted Answer

A current source in parallel with an impedance

Answer

Norton's equivalent circuit consists of an equivalent current source (IN) in parallel with an equivalent impedance (ZN).

Question 2

What is the phase angle of a series circuit with R = 30 Ω and XL = 40 Ω?

Accepted Answer

53.13°

Answer

θ = arctan(XL/R) = arctan(40/30) = arctan(1.333) ≈ 53.13°.

Question 3

In a parallel RLC circuit at resonance, the circuit impedance is:

Accepted Answer

Maximum

Answer

At resonance in a parallel RLC circuit, the impedance reaches its maximum value because the parallel LC combination presents infinite impedance.

Question 4

A 10 mH inductor carries a current that changes at 500 A/s. What is the induced EMF?

Accepted Answer

5 V

Answer

e = L(di/dt) = 0.010 H × 500 A/s = 5 V.

Question 5

The maximum power transfer theorem states that maximum power is delivered to a load when the load impedance equals:

Accepted Answer

The complex conjugate of the source impedance

Answer

Maximum power transfer occurs when ZL = Zs* (complex conjugate), meaning equal resistance and opposite sign reactance.

(EETC) Electrical Technician Certification Practice Test