A direct current (DC) circuit is monitored while a total charge of 180\text{ C} passes thr… — Armed Services Vocational Aptitude Battery (ASVAB)

A direct current (DC) circuit is monitored while a total charge of $180\text{ C}$ passes through a cross-section of a copper conductor over an elapsed time of $2\text{ minutes}$ . What is the magnitude of the resulting current, and in which direction do the free electrons drift through the conductor?

A
The current is $90\text{ A}$ , and electrons drift toward the positive terminal.
B
The current is $1.5\text{ A}$ , and electrons drift toward the negative terminal.
The current is $1.5\text{ A}$ , and electrons drift toward the positive terminal.Answer
D
The current is $1.5\text{ V}$ , and electrons drift toward the positive terminal.

Answer

The current is

1.5\text{ A}

, and electrons drift toward the positive terminal.

Current is defined as charge per unit time (

I = \frac{Q}{t}

). Converting

2\text{ minutes}

gives

120\text{ seconds}

, yielding

I = \frac{180\text{ C}}{120\text{ s}} = 1.5\text{ A}

. In metallic conductors, the mobile charge carriers are electrons; because electrons are negatively charged, electrostatic forces drive them away from the negative terminal and toward the positive terminal.

Step-by-Step Solution

Convert the elapsed time from minutes to the SI base unit of seconds.

t = 2\text{ min} \times 60\text{ s/min} = 120\text{ s}

An ampere is defined as one coulomb per second (

1\text{ A} = 1\text{ C/s}

), which requires time to be expressed in seconds.

Calculate the electric current using the charge rate formula

I = \frac{Q}{t}

I = \frac{180\text{ C}}{120\text{ s}} = 1.5\text{ A}

Current measures the rate at which electric charge flows past a specific point in a circuit.

Determine the physical direction of charge carrier movement in the metallic conductor.

Electrons drift toward the positive terminal.

In solid metal conductors like copper, current consists of free electrons that carry negative charge and are attracted toward the positive potential.

Key Concept

Electric current is the time rate of charge flow (

I = Q/t

), with physical electron flow moving from negative to positive potential.

Estimated Time:45s

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Answer

Step-by-Step Solution

Key Concept

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