ASVAB Electronics Information Practice Test 343684 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 voltage in this circuit if resistance is 100 Ω and current is 2.5 amps.

85% Answer Correctly

	251.5 V
	250 V
	275 V
	225 V

Solution

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

V = \( I \times R \) = \( 2.5 \times 100 \) = 250 V

You would measure the amount of resistance at a certain point in a circuit with a(n):

78% Answer Correctly

	ammeter
	voltmeter
	ohmmeter
	potentiometer

Solution

Resistance is opposition to the flow of current and is measured in ohms (Ω). An ohmmeter is used to measure the amount of resistance at a certain point in a circuit.

Which of the following will help to prevent a short circuit?

74% Answer Correctly

	resistor
	transistor
	diode
	fuse

Solution

Fuses are thin wires that melt when the current in a circuit exceeds a preset amount. They help prevent short circuits from damaging circuit components when an unusually large current is applied to the circuit, either through component failure or spikes in applied voltage.

Which of the following is not a characteristic of direct current?

48% Answer Correctly

	cannot easily travel distances without power loss
	electrons flow in only one consistent direction
	used to power your cell phone
	an example power source is a generator

Solution

Direct current flows in only one direction in a circuit, from the negative terminal of the voltage source to the positive. A common source of DC is a battery. 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.

Which of the following is not a characteristic of a step-up transformer?

54% Answer Correctly

	the secondary voltage is higher than the primary voltage
	has more turns in the secondary winding than in the primary winding
	the primary voltage is higher than the secondary voltage
	increases voltage

Solution

As their names indicate, a step-up transformer is used to step up or increase voltage and a step-down transformer is used to step down or decrease voltage. In a step-up transformer, the secondary voltage is higher than the primary voltage and it has more turns in the secondary winding than in the primary winding.