ISCET Electronic Components & Circuit Analysis 4

Question 1

Two resistors of 6 kΩ and 3 kΩ are connected in parallel. What is the equivalent resistance?

Accepted Answer

2 kΩ

Answer

Parallel resistance: 1/Req = 1/6k + 1/3k = 1/6k + 2/6k = 3/6k, so Req = 2 kΩ.

Question 2

What is the impedance of a pure inductor at DC (0 Hz)?

Accepted Answer

Zero

Answer

Inductive reactance XL = 2πfL equals zero at DC (f = 0 Hz), so a pure inductor is a short circuit at DC.

Question 3

In a BJT, the current gain β (beta) is defined as:

Accepted Answer

IC / IB

Answer

Beta (β or hFE) is the ratio of collector current to base current, typically ranging from 20 to 500 for common transistors.

Question 4

An electrolytic capacitor is installed with reversed polarity in a DC circuit. What will most likely occur?

Accepted Answer

It may overheat and fail catastrophically

Answer

Electrolytic capacitors are polarized; reverse polarity breaks down the oxide dielectric layer, causing excessive leakage current, heat, and possible explosion.

Question 5

What is the resonant frequency of a circuit with L = 10 mH and C = 10 μF?

Accepted Answer

503 Hz

Answer

fr = 1 / (2π√LC) = 1 / (2π√(0.01 × 0.00001)) = 1 / (2π × 3.16×10⁻⁴) ≈ 503 Hz.

(ISCET) International Society of Certified Electronics Technicians Practice Test

(ISCET) International Society of Certified Electronics Technicians Practice Test

ISCET Electronic Components & Circuit Analysis 4