Question 1

Impedance can be measured using&#10;A) Oscilloscope&#10;B) Lock-in amplifier&#10;C) FFT analyzer&#10;D) all of the above

Accepted Answer

Impedance can be measured using various electronic instruments, including oscilloscopes (when used with impedance probes), lock-in amplifiers (which can measure the magnitude and phase of an impedance), and FFT analyzers (which can analyze the frequency components of a signal and thus be used to measure impedance across different frequencies).

Question 2

The main purpose of using multi-sine instead of single sine is to ensure&#10;A) linearity&#10;B) causality&#10;C) stability&#10;D) shorter measurement time

Accepted Answer

Multi-sine signals are used instead of single sine signals primarily to reduce the measurement time. By simultaneously injecting multiple sine waves at different frequencies, it is possible to gather data across a wide frequency range in a shorter period, making the testing process more efficient.

Question 3

FFT of a time-domain signal would give&#10;A) magnitude only&#10;B) phase only&#10;C) both magnitude and phase&#10;D) signal to noise ratio

Accepted Answer

FFT (Fast Fourier Transform) of a time-domain signal calculates and returns both magnitude and phase information of the signal across different frequency components.

Question 4

Lock-in amplifiers can be used to simultaneously obtain all harmonics.

Accepted Answer

Lock-in amplifiers can only measure one frequency at a time, so they cannot simultaneously obtain all harmonics.

Question 5

Faraday cage is used to&#10;A) minimize the nonlinearity effects&#10;B) decrease measurement time&#10;C) minimize the effect of external noise&#10;D) minimize the instabilities

Accepted Answer

Faraday cage is used to minimize the effect of external noise, which can disrupt measurements or signals. It works by surrounding the equipment or signal source with a conductive material that blocks outside electromagnetic fields from entering and interfering with the signal.

Deck 2: Experimental Aspects