Back EMF Calculator

Main Category	Engineering ↺
Engineering	Electrical ↺
Electrical	Machine ↺
Machine	Dc Machine ↺

✖Voltage, electric potential difference, electric pressure, or electric tension is the difference in electric potential between two points, which is defined as the work needed per unit of charge to move a test charge between the two points.ⓘ Voltage [V]			+10% -10%
✖Armature Current is the Current which Flows in Armature Winding or rotating Winding of Motor or generator.ⓘ Armature Current [Ia]			+10% -10%
✖The Armature resistance is given is the opposition that a substance offers to the flow of electric current.ⓘ Armature resistance [Ra]			+10% -10%

✖Electromotive force is the capability of the system to make the charge flow.ⓘ Back EMF [ε]

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Credits

Urvi Rathod

Vishwakarma Government Engineering College (VGEC), Ahmedabad

Urvi Rathod has created this Calculator and 1000+ more calculators!

Team Softusvista

Softusvista Office (Pune), India

Team Softusvista has verified this Calculator and 1000+ more calculators!

Back EMF Solution

STEP 0: Pre-Calculation Summary

Formula Used

electromotive_force = Voltage-(Armature Current*Armature resistance)
ε = V-(Ia*Ra)
This formula uses 3 Variables

Variables Used

Voltage - Voltage, electric potential difference, electric pressure, or electric tension is the difference in electric potential between two points, which is defined as the work needed per unit of charge to move a test charge between the two points. (Measured in Volt)
Armature Current - Armature Current is the Current which Flows in Armature Winding or rotating Winding of Motor or generator. (Measured in Ampere)
Armature resistance - The Armature resistance is given is the opposition that a substance offers to the flow of electric current. (Measured in Ohm)

STEP 1: Convert Input(s) to Base Unit

Voltage: 120 Volt --> 120 Volt No Conversion Required
Armature Current: 0.5 Ampere --> 0.5 Ampere No Conversion Required
Armature resistance: 3 Ohm --> 3 Ohm No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

ε = V-(Ia*Ra) --> 120-(0.5*3)

Evaluating ... ...

ε = 118.5

STEP 3: Convert Result to Output's Unit

118.5 Volt --> No Conversion Required

FINAL ANSWER

118.5 Volt <-- Electromotive Force

(Calculation completed in 00.016 seconds)

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< 10+ Dc Machine Calculators

Constant Of The DC Machine

constant_of_the_dc_machine = Number of conductors*Number of pole/2*pi*Number of parallel paths Go

Series Generator Terminal Voltage

voltage = Induced voltage-(Armature Current*(Armature resistance+Series field resistance)) Go

Back EMF

electromotive_force = Voltage-(Armature Current*Armature resistance) Go

Shunt Generator Terminal Voltage

voltage = Induced voltage-(Armature Current*Armature resistance) Go

Shunt Field Current

shunt_field_current = Voltage/Shunt field resistance Go

Field Current

field_current = Voltage/Shunt field resistance Go

Armature Current

armature_current = Field Current+Load current Go

Power Generated When The Armature Current Is Given

power = Induced voltage*Armature Current Go

Angular Speed Of The Dc Machine

angular_speed = (2*pi*Motor Speed)/60 Go

Power Generated When Torque is Given

power = Angular Speed*Torque Go

Back EMF Formula

electromotive_force = Voltage-(Armature Current*Armature resistance)
ε = V-(Ia*Ra)

How does back EMF affect supply voltage?

As the back emf depends on the current their value also decreases. The magnitude of the back EMF is nearly equal to the supply voltage. If the sudden load is applied to the motor, the motor becomes slow down. As the speed of the motor decreases, the magnitude of their back emf also falls down.

How to Calculate Back EMF?

Back EMF calculator uses electromotive_force = Voltage-(Armature Current*Armature resistance) to calculate the Electromotive Force, The back emf opposes the supply voltage. The supply voltage induces the current in the coil which rotates the armature. The electrical work required by the motor for causing the current against the back emf is converted into mechanical energy. And that energy is induced in the armature of the motor. Electromotive Force and is denoted by ε symbol.

How to calculate Back EMF using this online calculator? To use this online calculator for Back EMF, enter Voltage (V), Armature Current (Ia) and Armature resistance (Ra) and hit the calculate button. Here is how the Back EMF calculation can be explained with given input values -> 118.5 = 120-(0.5*3).

FAQ

What is Back EMF?

The back emf opposes the supply voltage. The supply voltage induces the current in the coil which rotates the armature. The electrical work required by the motor for causing the current against the back emf is converted into mechanical energy. And that energy is induced in the armature of the motor and is represented as ε = V-(Ia*Ra) or electromotive_force = Voltage-(Armature Current*Armature resistance). Voltage, electric potential difference, electric pressure, or electric tension is the difference in electric potential between two points, which is defined as the work needed per unit of charge to move a test charge between the two points, Armature Current is the Current which Flows in Armature Winding or rotating Winding of Motor or generator and The Armature resistance is given is the opposition that a substance offers to the flow of electric current.

How to calculate Back EMF?

The back emf opposes the supply voltage. The supply voltage induces the current in the coil which rotates the armature. The electrical work required by the motor for causing the current against the back emf is converted into mechanical energy. And that energy is induced in the armature of the motor is calculated using electromotive_force = Voltage-(Armature Current*Armature resistance). To calculate Back EMF, you need Voltage (V), Armature Current (Ia) and Armature resistance (Ra). With our tool, you need to enter the respective value for Voltage, Armature Current and Armature resistance and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Electromotive Force?

In this formula, Electromotive Force uses Voltage, Armature Current and Armature resistance. We can use 10 other way(s) to calculate the same, which is/are as follows -

electromotive_force = Voltage-(Armature Current*Armature resistance)
shunt_field_current = Voltage/Shunt field resistance
armature_current = Field Current+Load current
voltage = Induced voltage-(Armature Current*Armature resistance)
field_current = Voltage/Shunt field resistance
constant_of_the_dc_machine = Number of conductors*Number of pole/2*pi*Number of parallel paths
power = Angular Speed*Torque
power = Induced voltage*Armature Current
angular_speed = (2*pi*Motor Speed)/60
voltage = Induced voltage-(Armature Current*(Armature resistance+Series field resistance))

Where is the Back EMF calculator used?

Among many, Back EMF calculator is widely used in real life applications like {FormulaUses}. Here are few more real life examples -
{FormulaExamplesList}

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