The resistance of the armature in the motor shown in Fig. 33-2 is 2.30 Ω. It draws a current of

step 1 Hi, for this question, want to find the back AMF when resistance of the armature is 2 .3 oms and

The resistance of the armature in the motor shown in Fig....

The resistance of the armature in the motor shown in Fig. $33-2$ is $2.30 \Omega$. It draws a current of $1.60$ A when operating on $120 \mathrm{~V}$. What is its back emf under these circumstances? The motor acts like a back emf in series with an $I R$ drop through its internal resistance. Therefore, or $$ \begin{array}{l} \text { Line voltage }=\text { back emf }+I r \\ \qquad \text { Back emf }=120 \mathrm{~V}-(1.60 \mathrm{~A})(2.30 \Omega)=116 \mathrm{~V} \end{array} $$

The resistance of the armature in the motor shown in Fig. $33-2$ is $2.30 \Omega$. It draws a current of $1.60$ A when operating on $120 \mathrm{~V}$. What is its back emf under these circumstances?
The motor acts like a back emf in series with an $I R$ drop through its internal resistance. Therefore,
or
$$
\begin{array}{l}
\text { Line voltage }=\text { back emf }+I r \\
\qquad \text { Back emf }=120 \mathrm{~V}-(1.60 \mathrm{~A})(2.30 \Omega)=116 \mathrm{~V}
\end{array}
$$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Back Electromotive Force (Back EMF)

Back EMF is the voltage generated internally by a motor when it is in operation. This generated voltage opposes the applied voltage driving the motor and results from the motor's rotation in a magnetic field. It is instrumental in limiting the current through the armature, thereby helping control the motor’s performance.

Voltage Drop in Series Circuits

When components are connected in series within a circuit, the total voltage is distributed across them in proportion to their resistances or impedances. Understanding how voltage drops are allocated among various circuit elements is essential for analyzing and designing electrical circuits.

Ohm’s Law

Ohm's Law is a core principle in electrical engineering, establishing the relationship between voltage, current, and resistance through the equation V = I × R. This law is fundamental when determining the voltage drop across a resistor in any circuit, which is necessary for understanding how applied voltages are split among components.

Transcript

Please give Ace some feedback