ASVAB Electronics 3

Question 1

A transformer has a primary winding of 500 turns and a secondary winding of 100 turns. If the primary voltage is 120V, what is the secondary voltage?

Accepted Answer

24V

Answer

The turns ratio (500:100 = 5:1) means the secondary voltage is 120V ÷ 5 = 24V.

Question 2

Which type of capacitor is polarized and must be connected with correct polarity in a circuit?

Accepted Answer

Electrolytic

Answer

Electrolytic capacitors are polarized due to their construction and will be damaged if connected in reverse polarity.

Question 3

What is the function of a diode in an AC circuit when used as a half-wave rectifier?

Accepted Answer

Allows current to flow in only one direction

Answer

A diode passes current in only one direction, so it blocks the negative half-cycle of AC, producing pulsating DC.

Question 4

In a series RLC circuit at resonance, which statement is TRUE?

Accepted Answer

Impedance is at minimum and equals R

Answer

At resonance, XL equals XC and they cancel, leaving only resistance R as the total impedance.

Question 5

What does a multimeter measure when set to the 'ohms' setting?

Accepted Answer

Resistance

Answer

The ohms setting measures electrical resistance; the meter applies a small voltage and measures the resulting current to calculate resistance.

ASVAB - Armed Services Vocational Aptitude Battery Practice Test