ASVAB Electronics Information Practice Test 140770 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.40
Score	0%	68%

Review

1 Use Ohm's Law to calculate the value of current in this circuit if voltage is 105 volts and resistance is 70 Ω.

81% Answer Correctly

	2.25 A
	1.65 A
	1.5 A
	3.5 A

Solution

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

Solved for current, I = \( \frac{V}{R} \) = \( \frac{105}{70} \) = 1.5 A

In an electronic circuit, a thermocouple can be used to:

42% Answer Correctly

	increase or decrease the temperature of a component in the circuit
	open or close a circuit at a designated temperature
	keep the circuit at a designated safe temperature
	link the temperature of one component in the circuit to that of another component in the circuit

Solution

A thermocouple is a temperature sensor that consists of two wires made from different conductors. The junction of these two wires produces a voltage based on the temperature difference between them and can be used like a switch to open or close the circuit at a designated temperature.

Which of these materials is not a good conductor of electricity?

79% Answer Correctly

	tin
	copper
	gold
	air

Solution

All conductors have resistance and the amount of resistance varies with the element. In general, metals make the best conductors of electricity and non-metals make the worst conductors of electricity.

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

61% Answer Correctly

	resists
	eliminates
	doubles
	enhances

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.

Which of the following statements about a capacitor is false?

77% Answer Correctly

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

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.