CBET Basic 3

Question 1

Which law states that the algebraic sum of all currents entering and leaving a node equals zero?

Accepted Answer

Kirchhoff's Current Law

Answer

Kirchhoff's Current Law (KCL) is based on conservation of charge: all current entering a junction must equal all current leaving it.

Question 2

What is the purpose of a Zener diode in a circuit?

Accepted Answer

Regulate voltage by allowing reverse breakdown at a fixed voltage

Answer

A Zener diode operates in reverse breakdown at a stable, predictable voltage, making it ideal for voltage regulation.

Question 3

In biomedical equipment, which frequency range is used by most diathermy units?

Accepted Answer

300 kHz – 5 MHz

Answer

Surgical diathermy (electrosurgical units) operates in the radiofrequency range of approximately 300 kHz to 5 MHz to cut and coagulate tissue without nerve stimulation.

Question 4

Which mathematical relationship describes exponential decay in an RC circuit?

Accepted Answer

V(t) = V₀ × e^(-t/RC)

Answer

Voltage across a discharging capacitor decays exponentially as V(t) = V₀ × e^(-t/RC), where RC is the time constant.

Question 5

What is the function of an op-amp configured in a non-inverting amplifier topology?

Accepted Answer

Amplifies the input signal with positive gain and no phase inversion

Answer

A non-inverting op-amp configuration amplifies the input signal with gain = 1 + (Rf/Rin) and maintains the same phase as the input.

CBET - Certified Biomedical Equipment Technician Practice Test

CBET - Certified Biomedical Equipment Technician Practice Test

CBET Basic 3