ISCET Test Equipment and Measurement 2

Question 1

When using an oscilloscope to measure a signal, the timebase is set to 2 ms/div and you count 4 divisions for one complete cycle. What is the frequency of the signal?

Accepted Answer

125 Hz

Answer

Period = 4 divisions × 2 ms/div = 8 ms; frequency = 1/0.008 s = 125 Hz.

Question 2

A clamp-on ammeter measures current by sensing which electrical property?

Accepted Answer

The magnetic field surrounding the conductor

Answer

A clamp meter uses a current transformer that responds to the magnetic field produced by current flowing through the conductor.

Question 3

On a spectrum analyzer, the resolution bandwidth (RBW) setting primarily controls which display characteristic?

Accepted Answer

The ability to distinguish two closely spaced signals

Answer

A narrower RBW filter allows the analyzer to resolve signals that are close together in frequency.

Question 4

Which DMM function would you select to test whether a diode junction is forward-biased and intact?

Accepted Answer

Diode test mode

Answer

The diode test mode applies a small forward voltage and displays the junction voltage drop (typically 0.5–0.7 V for silicon).

Question 5

A signal generator's output impedance is specified at 50 Ω. To avoid reflections and achieve maximum power transfer to the load, the load impedance should be:

Accepted Answer

50 Ω

Answer

Maximum power transfer and reflection-free operation occur when load impedance matches source impedance.

(ISCET) International Society of Certified Electronics Technicians Practice Test

(ISCET) International Society of Certified Electronics Technicians Practice Test

ISCET Test Equipment and Measurement 2