CABT Fundamentals of Electronics 3

Question 1

In a full-wave bridge rectifier, how many diodes are required?

Accepted Answer

4

Answer

A full-wave bridge rectifier uses 4 diodes arranged so that current flows through the load in the same direction for both AC half-cycles.

Question 2

What is the primary advantage of using a switching power supply over a linear power supply in biomedical equipment?

Accepted Answer

Higher efficiency and smaller size

Answer

Switching power supplies operate at high frequencies allowing smaller transformers and capacitors, resulting in higher efficiency (often >85%) and reduced size/weight.

Question 3

A Wheatstone bridge is balanced when:

Accepted Answer

R1/R2 = R3/R4

Answer

The Wheatstone bridge is balanced (zero galvanometer current) when the ratio of resistances in each arm are equal: R1/R2 = R3/R4.

Question 4

In digital logic, what is the output of a NAND gate when both inputs are HIGH?

Accepted Answer

LOW

Answer

A NAND gate outputs LOW only when all inputs are HIGH; it is the complement of an AND gate.

Question 5

What phenomenon occurs when an AC signal causes a transistor to conduct during only part of the input cycle in Class B amplification?

Accepted Answer

Crossover distortion

Answer

Crossover distortion occurs at the zero-crossing point in Class B push-pull amplifiers due to the transistor's 0.6V threshold voltage.

(CABT) Certified Associate in Biomedical Technology Practice Test

(CABT) Certified Associate in Biomedical Technology Practice Test

CABT Fundamentals of Electronics 3