An avionics technician reads a specification sheet indicating that an auxiliary battery pr… — Armed Services Vocational Aptitude Battery (ASVAB)

An avionics technician reads a specification sheet indicating that an auxiliary battery provides an electromotive force (EMF) of $28\text{ V}$ . What does this $28\text{ V}$ EMF rating fundamentally represent?

The battery supplies $28\text{ joules}$ of electrical energy for every $1\text{ coulomb}$ of charge moved.Answer
B
The battery maintains a continuous current flow of $28\text{ coulombs}$ of charge per second.
C
The battery exerts an internal opposition to electron flow equal to $28\text{ ohms}$ .
D
The battery produces alternating polarity reversals at a rate of $28\text{ cycles}$ per second.

Answer

The battery supplies

28\text{ joules}

of electrical energy for every

1\text{ coulomb}

of charge moved.

Electromotive force (EMF), measured in volts, represents the electrical potential energy imparted to charge carriers by a source. By definition, one volt equals one joule of energy per one coulomb of charge (

1\text{ V} = 1\text{ J/C}

). Therefore, a

28\text{ V}

rating indicates that the battery supplies

28\text{ joules}

of energy for each coulomb of charge transferred.

Step-by-Step Solution

Recall the fundamental physical definition of electromotive force (EMF) and electric potential difference.

Voltage (

V

) is defined as electrical work or energy (

W

) per unit charge (

Q

), expressed by the formula

V = \frac{W}{Q}

Electromotive force represents the electric pressure or energy supplied to charge carriers by a power source.

Apply the standard units of measurement to the voltage formula.

1\text{ volt} = 1\text{ joule per coulomb}

(

1\text{ V} = 1\text{ J/C}

Joules measure energy or work done, while coulombs measure quantity of electric charge.

Evaluate a potential difference of

28\text{ V}

using these units.

A rating of

28\text{ V}

means

28\text{ joules}

of electrical energy are supplied to each coulomb of charge.

Direct multiplication:

28\text{ V} = 28\text{ J/C}

Key Concept

Voltage and Electromotive Force (EMF) as electrical potential energy per unit charge (

1\text{ V} = 1\text{ J/C}

)

Estimated Time:1m 0s

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