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Unit of Electricity

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Last updated date: 25th Apr 2024
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An introduction to the Units of Electricity

The standard unit of electricity is defined in a systematic way. First, the ampere is defined. After, the ampere comes from the charge and coulomb of an electron.

 

The SI units to measure the electric expressions of voltage, resistance and current are Volt (v), Ohm (Ω) and Ampere (A), respectively.

 

The electrical units for measurement of electric expressions are based on the International System (SI) of units. Other units are derived from this si unit of electricity.

 

The units are used in electric circuits, electronics and electric appliances to measure and describe their capacity from small to large.

 

Standard Electrical Units of Measure


Electrical Parameter

Measuring Unit

Unit/Symbol

Formula

Voltage

Volt

V or E

V = I × R

Resistance

Ohm

R or Ω

R = V / I

Current

Ampere

I or i

I = V / R

Capacitance

Farad

C

C = Q / V

Conductance

Siemen

G

G = 1 / R

Charge

Coulomb

C

Q = C×V

Power

Watts

W

P = V × I or $I^2$ × R

Inductance

Henry

L/H

VL = -L(di/dt)

Frequency

Hertz

Hz

f = 1 / T

Impedance

Ohm

Z

Z² = R²+X²

 

Standard Units (Multiples And Submultiples)

There is a huge range of electric values between a minimum value and a maximum value of a standard electric unit. For example, the resistance of a conductor can be as low as 0.001 ohms and as high as 100000 ohms. We can avoid writing multiple zeros while describing the values of the electric unit, if we use sub-multiples and multiple values of the standard unit. Below mentioned is a table with their names and abbreviation.

 

Prefix

Symbol

Multiplier

Power of ten

pico

1/1,000,000,000,000

p

1012

nano

1/1,000,000,000

n

109

micro

1/1,000,000

μ

106

mini

1/1,000

m

103

centi

1/100

c

102

none

1

none

100

kilo

1,00

c

10-2

kilo

1,000

K

10-3

Mega 

1,000,000,

M

10-6

Giga 

1,000,000,000,

G

10-9

 

Below mentioned is a set of points that describes the use of units or multiple units of resistance, current and voltage.

● 1kV = 1 kilo-volt = 1,000 Volts.

● 1kΩ = 1 kilo-ohms = 1 thousand Ohms.

● 1mA = 1 milli-amp = one-thousandths (1/1000) of an Ampere.

● 1kW = 1 kilo-watt = 1,000 Watts.

● 100uF = 100 microfarads = 100 millionths (100/1,000,000) of a Farad.

● 1MHz = 1 mega-hertz = one million Hertz.

 

While converting one prefix to another, we have to multiply or divide the difference between the two values.

 

What Are The Basic Units Of Electricity?

Voltage/Volts (V) - The amount of work required to move an electric charge from one point to another is called voltage.

 

Current (I)/Amps (A) - Current is defined as the amount of charge (or electrons) passing through a circuit per unit of time.

 

Resistance (R) /Ohms (O) - Resistance is the opposition offered to the flow of current in a circuit.

 

Power (P)/Watts (W) - Power is defined as the product of the work required and the number of electrons passing through the circuit per unit time.

 

Other Electricity Units

Just like the standard units, other units are used to denote the values and quantities. They are:

 

Wh – The Watt-Hour is defined as the amount of electric energy consumed by an electric circuit over a given time duration. For example, a normal electric bulb consumes 100 watts of power per hour.

 

dB – A Decibel is a one-tenth unit of Bel (symbol B). It is used to represent a gain in voltage, power or current.

 

θ – Phase Angle. It is the difference (in degrees) between the voltage waveform and the current waveform, which have the same time period. It is a time difference that depends upon the circuit element. Its value can be “leading” or “lagging”. It is also measured in radians.

 

ω – Angular Frequency is used in AC circuits to represent phase relation between two waveforms.

 

τ – Time Constant, The Time Constant is a characteristic of an impedance circuit. It is the time taken by the output to reach 63.7% of its minimum or maximum value when subjected to step response input. It is a measure of time reaction.

 

SI Unit of charge

The SI unit of electric charge is the coulomb. A coulomb is defined as an ampere second.

 

The Units of Electric Charge are Listed in The Table Mentioned Below


Name

Symbols

Context

Alternate Spellings

prefixes

coulomb

C

SI

coulombs

SI

stacoulomb

statC

ESU

statcoulombs

SI

abcoulomb

abC

EMU

ab coulombs

SI

fanklin

f

Standard

franklins

SI

electron

e

Atomic

electrons

SI

Planck_charge


planck

planck_charges



These are the units of electric charge.

 

Do You Know?

There is nothing like “1 unit electricity”.

 

Throughout the world, there is one type or another type of measurement which has been taken as a base amount of electric power. 1KWh is a mainly used unit of power. It is the amount of electric power consumed in 1 hour by an electric appliance of 1000 W (1KW).

 

Electricity is Measured in Units of Electricity.

If you've ever looked at an electricity bill, you'll notice that the unit of electricity is usually expressed in kilowatt-hours (kWh). The unit, in this case, reflects the actual measure of electricity or the amount of energy consumed at a location. So, if you've ever wondered what the unit of electricity is, the answer is below.


Electricity is Measured in Units of SI.

When it comes to the SI unit of electricity, the unit of power is Watt. The name was preserved in honor of James Watt, the inventor of the steam engine. Watt is usually equal to one ampere under one volt of pressure, however, electricity, which is a bigger quantity, is measured in kilowatt-hours (kWh).

  • Electricity Unit - Standard Units

The Volt [V], Ampere [A], and Ohm [] are the standard units of electrical measurement for voltage, current, and resistance, respectively.


Other commonly used electrical units are derived from SI base units. These electrical units of measurement are based on the International (metric) System, generally known as the SI System.


When the amounts being measured are very big or very small, it is often essential to employ multiples or sub-multiples (fractions) of these basic electrical measuring units in electrical or electronic circuits and systems.


Electrical Units of Measurement


Electrical Parameter

Measuring Unit

Symbol

Description

voltage

volt

V or E

Unit of Electrical Potential
V = I x R

Current 

Ampere

I or i

Unit of Electrical Current I = V / R

Resistance 

ohm

R or Ω

Unit of DC Resistance R= V/I

Conductance

Siemen

G or ປ

Reciprocal of Resistance G = 1/R

Charge 

Coulomb

Q

Unit of Electrical Charge Q = C x V

Inductance

Henry 

L or H

Unit of Inductance
VL = L(di/dt)

Power 

Watts

W

Unit of Power
P = V x I or I2 x R

Impedance

Ohm

Z

Unit of AC Resistance Z2 = R2 + X2


What Are The Four Basic Electricity Units?

The four fundamental units of electricity are:

  • Voltage is the amount of effort necessary to transfer one electric charge from one location to another. The volt is the measurement unit.

  • Current is the amount of charge that passes through a circuit in a certain amount of time. The unit is ampere.

  • The opposition provided by the current flow in the circuit is known as resistance. The units are ohms.

  • The product of work done and the number of electrons travelling through the circuit in a certain amount of time is called power. The watt is the measurement unit.


Volts, amps, ohms, and watts are the four basic units of electricity.


Stay tuned to Vedantu for further information on other concepts, such as the volt.


Units of Electricity (Others)

There are other conventional units of measurement for electrical qualities other than watt and kilowatt, such as voltage, resistance, power, capacitance, inductance, and others. Some common electricity units are listed below.


Electrical Parameter

Measuring Unit

Symbol

Voltage

Volt

V or E

Resistance

Ohm

R or Ω

Capacitance

Farad

C

Charge

Coulomb

Q

Inductance

Henry

L or H

Frequency

Hertz

HZ

Conductance

Siemen

G or ປ

FAQs on Unit of Electricity

1. How to Convert 1MHz into kHz?

1 kHz is equal to one thousand (1,000,) hertz, and 1 MHz is equal to one million (1,000,000) hertz. So, one 1MHz is one thousand times larger than 1kHz. Then to convert megahertz into Kilo-hertz, we have to multiply megahertz by 1000 because 1 MHz is equal to 1000 kHz. It can be well studied with the help of the Unit of Electricity - Standard Units, Basic Units and Other Units provided by Vedantu. You’ll be able to know conversions and work on the basic concepts of the Unit of electricity. 

2. What is the Commercial Unit of Electricity?

The primarily applied commercial unit of electricity is kWh. It is the energy expended by a source of 1 KW in a time duration of one hour. It is not a standard unit in the formal system but is used in electric appliances. The electric energy used in factories, industries and houses which are measured in kWh. The application and concepts to understand the Unit of Electricity - Standard Units, Basic Units and Other Units can be studied with Vedantu.

3. What is the State Of the dB Ratio of An Input Voltage To An Output Voltage?

The dB ratio of an input voltage (VIN) for that of an output voltage (Vout) is expressed as 20log10(Vout/Vin). This value can either be positive (20dB), which represents gain or negative (-20dB) which represents loss, and a value of 0 represents unity i.e input = output expressed by 0 dB. Download the free pdf from Vedantu with the Unit of Electricity - Standard Units, Basic Units and Other Units. 

4. How Are Units Of Electricity Measured?

Electricity is measured by electric meters in kilowatt-hours (kWh), or Units. Subtracting the old electricity meter reading from the current meter reading gives the units of current used. It is defined as the actual electricity or energy utilized. If you go for 1000 Watts or 1 Kilowatt of power for 1 hour then you consume 1 unit or 1 Kilowatt-Hour (kWh) of electricity. Download the PDF from Vedantu now. The Unit of Electricity - Standard Units, Basic Units and Other Units can help you with the proper understanding of the concepts.

5. Is the Unit of Electricity - Standard Units, Basic Units and Other Units important to study?

The Unit of Electricity - Standard Units, Basic Units and Other Units is an important subject in physics. Students should get thorough knowledge about the concepts and basic understanding of the unit of electricity along with its units. It is essential to solving the questions based on the same and students will be able to calculate the required electricity-related problems. You can join the coaching classes provided by Vedantu. They provide a free trial of seven days. Download the PDF now.

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