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Back EMF Equation of DC Motor Formula

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The Back emf opposes the current which causes it in any dc machine. Check FAQs

E b = \frac{n \cdot Φ \cdot Z \cdot N}{60 \cdot n ||}

E_b - Back EMF?n - Number of Poles?Φ - Magnetic Flux?Z - Number of Conductors?N - Motor Speed?n_|| - Number of Parallel Paths?

Back EMF Equation of DC Motor Example

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Here is how the Back EMF Equation of DC Motor equation looks like with Values.

Here is how the Back EMF Equation of DC Motor equation looks like with Units.

Here is how the Back EMF Equation of DC Motor equation looks like.

24.9433 = \frac{4 \cdot 1.187 \cdot 14 \cdot 1290}{60 \cdot 6}

24.9433V = \frac{4 \cdot 1.187Wb \cdot 14 \cdot 1290rev/min}{60 \cdot 6}

24.9433 = \frac{4 \cdot 1.187 \cdot 14 \cdot 1290}{60 \cdot 6}

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Back EMF Equation of DC Motor Solution

Follow our step by step solution on how to calculate Back EMF Equation of DC Motor?

FIRST Step Consider the formula

E b = \frac{n \cdot Φ \cdot Z \cdot N}{60 \cdot n ||}

Next Step Substitute values of Variables

∴

E b = \frac{4 \cdot 1.187Wb \cdot 14 \cdot 1290rev/min}{60 \cdot 6}

Next Step Convert Units

∴

E b = \frac{4 \cdot 1.187Wb \cdot 14 \cdot 135.0885rad/s}{60 \cdot 6}

Next Step Prepare to Evaluate

∴

E b = \frac{4 \cdot 1.187 \cdot 14 \cdot 135.0885}{60 \cdot 6}

Next Step Evaluate

∴

E b = 24.9433380970217V

LAST Step Rounding Answer

∴

E b = 24.9433V

Back EMF Equation of DC Motor Formula Elements

Variables

Back EMF

The Back emf opposes the current which causes it in any dc machine.

Symbol: E_b

Measurement: Electric PotentialUnit: V

Note: Value can be positive or negative.

Formulas to find Back EMF

Number of Poles

Number of Poles is defined as the number of poles in an electrical machine for the flux generation.

Symbol: n

Measurement: NAUnit: Unitless

Note: Value should be greater than 0.

Formulas to find Number of Poles

Magnetic Flux

Magnetic flux (Φ) is the number of magnetic field lines passing through the magnetic core of an electrical dc motor.

Symbol: Φ

Measurement: Magnetic FluxUnit: Wb

Note: Value should be greater than 0.

Formulas to find Magnetic Flux

Number of Conductors

The number of conductors is the variable we use for getting the correct number of conductors placed in the rotor of a dc motor.

Symbol: Z

Measurement: NAUnit: Unitless

Note: Value can be positive or negative.

Formulas to find Number of Conductors

Motor Speed

Motor Speed is the speed of the rotor(motor).

Symbol: N

Measurement: Angular VelocityUnit: rev/min

Note: Value can be positive or negative.

Formulas to find Motor Speed

Number of Parallel Paths

The Number of Parallel Paths in a DC machine refers to the number of independent paths for current to flow in the armature winding.

Symbol: n_||

Measurement: NAUnit: Unitless

Note: Value can be positive or negative.

Formulas to find Number of Parallel Paths

Other formulas in DC Motor Characteristics category

Go Machine Construction Constant of DC Motor

K f = \frac{V s - I a \cdot R a}{Φ \cdot N}

Go Supply Voltage given Electrical Efficiency of DC Motor

V s = \frac{ω s \cdot τ a}{I a \cdot η e}

Go Armature Current given Electrical Efficiency of DC Motor

I a = \frac{ω s \cdot τ a}{V s \cdot η e}

Go Armature Torque given Electrical Efficiency of DC Motor

τ a = \frac{I a \cdot V s \cdot η e}{ω s}

How to Evaluate Back EMF Equation of DC Motor?

Back EMF Equation of DC Motor evaluator uses Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths) to evaluate the Back EMF, Back EMF Equation of DC motor shows that a motor has coils turning inside magnetic fields, and a coil turning inside a magnetic field induces an EMF. This EMF, known as the back EMF, acts against the applied voltage that's causing the motor to spin in the first place and reduces the current flowing through the coils of the motor. Back EMF is denoted by E_b symbol.

How to evaluate Back EMF Equation of DC Motor using this online evaluator? To use this online evaluator for Back EMF Equation of DC Motor, enter Number of Poles (n), Magnetic Flux (Φ), Number of Conductors (Z), Motor Speed (N) & Number of Parallel Paths (n_||) and hit the calculate button.

FAQs on Back EMF Equation of DC Motor

What is the formula to find Back EMF Equation of DC Motor?

The formula of Back EMF Equation of DC Motor is expressed as Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths). Here is an example- 24.94334 = (4*1.187*14*135.088484097482)/(60*6).

How to calculate Back EMF Equation of DC Motor?

With Number of Poles (n), Magnetic Flux (Φ), Number of Conductors (Z), Motor Speed (N) & Number of Parallel Paths (n_||) we can find Back EMF Equation of DC Motor using the formula - Back EMF = (Number of Poles*Magnetic Flux*Number of Conductors*Motor Speed)/(60*Number of Parallel Paths).

Can the Back EMF Equation of DC Motor be negative?

Yes, the Back EMF Equation of DC Motor, measured in Electric Potential can be negative.

Which unit is used to measure Back EMF Equation of DC Motor?

Back EMF Equation of DC Motor is usually measured using the Volt[V] for Electric Potential. Millivolt[V], Microvolt[V], Nanovolt[V] are the few other units in which Back EMF Equation of DC Motor can be measured.

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Back EMF Equation of DC Motor Formula

Back EMF Equation of DC Motor Example

Back EMF Equation of DC Motor Solution

Back EMF Equation of DC Motor Formula Elements

Other formulas in DC Motor Characteristics category

How to Evaluate Back EMF Equation of DC Motor?

FAQs on Back EMF Equation of DC Motor

Variable Name