ASVAB Electronics Information Practice Test 354647 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.66
Score	0%	73%

Review

Which of the following statements about a capacitor is false?

77% Answer Correctly

	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
	it is safe to touch a capacitor with your hands as long as it is small
	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.

This circuit component symbol represents a(n):

66% Answer Correctly

	transformer
	DC source
	transistor
	AC source

Solution

In contrast to the constant one-way flow of direct current, alternating current changes direction many times each second. Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances.

3 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

	2997 W
	3001.5 W
	4500 W
	3000 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.

Electricity cannot flow...

72% Answer Correctly

	through a circuit under load
	through a closed circuit
	through an open circuit
	through a circuit with resistance

Solution

An electrical circuit is a path through which electricity flows. This path contains one or more components that create a load (something that is using electricity) and that load acts as resistance to the passage of electricity through the circuit. Electricity can only flow through a circuit when the path is closed and cannot flow through an open circuit.

A capacitor is often used for which of the following purposes?

68% Answer Correctly

	to convert alternating current into direct current
	to maintain power in a circuit when the primary power source is disconnected
	as a primary power source
	to allow a small amount of current to control a large amount of current

Solution

Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.