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What Is A Negative Voltage [Everything You Need To Know]

You might have heard about negative voltage during every discussion about electricity. Voltage is the prime factor of electrical circuits and related factors. It’s natural to not know about negative voltages. It’s not the end of the world. 

And to give you a clear idea on this, I’ve answered your question!

What is a negative voltage?

A negative loop voltage is a voltage with a negative polarity greater than loop ground. Depending on the direction of the circuit, the voltage source can be positive or negative. If the voltage source has a  negative voltage, the negative terminal of the battery will connect to the positive side of the circuit. And it’ll connect the positive terminal to the negative side of the circuit. 

Still, confused? It’s cool. Learn more with my complete guide on negative voltage. Come on!

But First: What Is Voltage?

Voltage is the force that a power source exerts on a charged electron (current) in a conductor loop. This allows it to perform tasks such as the ignition of light.

In short, voltage is equal to pressure and measured in volts (V). This phrase pays homage to the Italian physicist Alessandro Volta (1745-1827). He invented the Voltaic column, the predecessor of today’s household batteries. 

Negative Voltage: 101 Facts

If you want to learn everything about negative voltage, you are at the right place. I have broken down the whole concept of negative voltage and how it works into different segments. This will help you understand and grasp the concept better and for a lifetime.

So keep reading to know what nev=negative voltage really is! 

Negative Voltage: The Basic Definition

Well, you might question why electricity goes to the ground. Iit is because the voltage is measured by the number of electrons that are passed through the test of the ground lead.

Just like that, the negative voltage in a circuit is voltage with a polarity that is more negative than the circuit’s ground. The second circuit is exactly the reverse. With the positive end of the voltage source connected to the ground but not the negative end.

In easy words, from the instrument’s point of view, this means that the flow of electrons has changed direction. 

For example, Let’s say you connect a multimeter to a car battery from red to red and black to black. You’ll notice a positive voltage on read. If you reverse the battery pole, the multimeter will display a negative voltage. 

The voltage is negative because the flow of electrons to the multimeter is reversed. Therefore, positive and negative refer to the direction in which the electrons flow through the wire

Difference Between Positive And Negative Voltage

When I say negative voltage, naturally your mind will take you to positive voltage. You would want to know their basic difference and more. Don’t worry, I’ve got you covered on that as well. 

You’ll find the basic differences I have prepared for you down below-

Positive VoltageNegative Voltage
Electrons flow from low to high density Electrons flow from high to low density
Polarity (+ to -) Polarity (- to +)
The positive side of the voltage is connected to the negative side of the voltageThe negative side of the voltage is connected to the positive side of the voltage
Used in Nintendo game switches, remotes etc.Used in transistors, op amp circuits etc.

Uses Of Negative Voltage

A negative voltage is used in a few fields of electrical circuits. These are the only fields where a negative voltage is used. Not knowing the uses of negative voltage is nothing unusual. 

Hence, I’ve tried to explain all the uses of negative voltage in easy words for you. Check them out-

Used in A Single Transistors 

In a transistor, the emitter’s electrons get repulsed by negative voltage. It occurs after the negative voltage is placed in the emitter’s lead. This is the process of forcing electrons to flow from emitter to collector. 

Thus, producing current on the way. This could also be called the transistor biasing method.

Used In Multi Transistors

The op amp circuit, which consists of multiple transistors, is a device that uses negative voltage. Dual power supplies are used by multiple op amps. A positive voltage is applied to one line of the op amp and a negative voltage is applied to the other line.

Measuring A Negative voltage

Now you know quite a lot about negative voltage. But you may still be wondering, how to measure this voltage. Well measuring a negative voltage is no different than measuring a positive one.

It’s the same as the one you’d use to check the voltage for using bedroom lights and outlets on the same circuit. But I have still mentioned the two tools I generally used to measure negative voltage. This is what you’re supposed to use-

  • Multimeter: To measure the voltage orientation 
  • Voltmeter: To place the multimeter on.
  • Batteries: To test the positive or negative voltage

In case you need a voltmeter, take a look at my suggestions below-

Product 1
Product 2

You surely won’t be disappointed by these voltmeters as they’re quite durable and easy to use.

How To Measure Negative Voltage?  

First, place the ground test lead of the multimeter leveling it with the ground. It’s important to touch it with the ground circuit for the appropriate reading results.

Then place the positive lead of the battery contracting it with the positive side of the circuit. Now start observing. If the battery has a positive voltage, its voltage with respect to the ground will be more positive. 

Hence, it will start delivering negative current to the positive part of the circuit.

If the battery orientation is a negative voltage, then its voltage will be more on the negative side with respect to the ground. And, it will start delivering a positive current to the negative part of the circuit.

Final Word

Negative voltages are necessary for powering various transformer-like devices. The system of voltage that measures below the ground is a negative voltage. It’s also known as zero voltage for its properties. 

Negative voltages generate electrical power in our homes. So in case, your circuit has low voltage on one leg, it’s probably due to negative voltage. Now you know that negative voltage is fiercely important for powerups.


Is it possible for voltage to be negative?

Answer: Yes, a voltage magnitude can be both positive and negative.

Can negative voltage go positive?

Answer: Yes it can. As an electrical circuit flows in one direction, the negative terminal will flow back at the positive terminal and vice-versa.

Is it possible for negative voltage to ground on batteries?

Answer: The negative terminal of the battery attaches to the body of your car. and then, you can connect the negative terminal of your siren to the nearest ground point (car metal body).


If you have come so far, I hope you learned all about negative voltage. I understand these heavy terms that we all skipped in physics class might be hard to digest. But I hope this article could clear up a few of your confusion.

If you’re still struggling feel free to contact a professional. 

Until next time. Goodbye!