ASVAB Electronics Information Practice Test 664619 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.53
Score	0%	71%

Review

1 A circuit with a 120-volt power supply is protected by a 25-amp circuit breaker. What is the largest number of watts loads on this circuit can safely use?

82% Answer Correctly

	3300 W
	3000 W
	6000 W
	1500 W

Solution

Wattage is current multiplied by voltage: W = IV. So, the maximum amount of power a 120-volt circuit with a 25A circuit breaker would allow is 120V x 25A = 3000 W.

An inductor __________ changes in the electric current flowing through it.

61% Answer Correctly

	enhances
	resists
	eliminates
	doubles

Solution

An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.

A transistor works by allowing a small amount of current to control general current flow. Where is the small amount of current applied?

55% Answer Correctly

	collector
	input
	base
	emitter

Solution

The transistor is the foundation of modern electronic devices. It is made entirely from semiconductor material (making it a solid state device) and can serve many different functions in a circuit including acting as a switch, amplifier, or current regulator. A transistor works by allowing a small amount of current applied at the base to control general current flow from collector to emitter through the transistor.

The formula specifying Ohm's law is which of the following?

76% Answer Correctly

	V = I²R
	\(V = {R \over I}\)
	\(V = {I \over R}\)
	V = IR

Solution

Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.

Which of the following statements about a capacitor is false?

77% Answer Correctly

	it is safe to touch a capacitor with your hands as long as it is small
	a capacitor remains charged even after the input voltage is removed
	to discharge a capacitor safely, use a high-wattage resistor comparable to the capacitance of the capacitor
	you should always discharge any capacitors before working on an electronic circuit

Solution

The purpose of a capacitor is to retain electric charge and it will do so even after its input voltage is removed. After the input voltage is removed, the capacitor will slowly discharge but, depending on the size and characteristics of the capacitor, discharging could take from a few minutes to a few years. So, it's never safe to touch a capacitor with your hands and you should make sure to discharge any capacitors in a circuit before working on it using an appropriately high-wattage resistor or a capacitor discharge tool.